header advert
Orthopaedic Proceedings Logo

Receive monthly Table of Contents alerts from Orthopaedic Proceedings

Comprehensive article alerts can be set up and managed through your account settings

View my account settings

Visit Orthopaedic Proceedings at:



Volume 91-B, Issue SUPP_I March 2009

K.E. Gill J. Edge

The optimum design for the femoral component for cementless Total Hip Replacement is not known. We conducted an ethically approved, randomized and prospective trial to compare two radically different designs of fully hydroxyapatite(HA) coated femoral stems. We compared the original JRI Furlong stem with the Wright Anca fit stem which is more anatomical in design. The paper discusses the merits and disadvantages of these two stems. The same acetabular component was used in both samples. The only variable was the stem shape.

All patients placed on the senior authors’ waiting list for primary THR were asked if they would enter the trial. There were no restrictions for selection to the sample. Patients were then randomised for one of the two stems. The surgery was undertaken by one surgeon, in one centre, in matched patients and using the same well-tried CSF acetabular cup and bearings.

335 patients had been entered into the trial, 228 females and 126 males.

191 patients had the JRI furlong hip implanted (57%) and 146 are in the Anca sample (43%).

The number of perioperative fractures in the Furlong group was 13(6.8%)and in the Anca sample 22 (15.3%).

The periprosthetic and perioperative fracture rates for the two stems were found to be significantly different at three years into the study and the trial was stopped. The possible reasons for this difference are discussed.

J. Boldt J. Cartillier A. Machenaud J. Vidalain

We present a prospective study focused on radiographic long-term outcomes and bone remodeling at a mean of 17.0 years (range: 15 to 20) in 208 cementless fully HA-coated femoral stems (Corail®, DePuy, Johnson & Johnson). Total hip replacements in this study were performed by three members of the surgeon design team (Artro Group) in France between 1986 and 1991. Radiographic evaluation focused on periprosthetic osteolysis, bone remodeling, osseous integration, subsidence, metaphyseal or diaphyseal load transfer, and femoral stress shielding. The radiographs were digitized and examined with contrast enhancing software (DICOM Anonymizer 1.1.2) for analysis of the trabecular architecture. Radiographic signs of aseptic stem loosening were visible in two cases (1%). Three stems (1.4%) showed metaphyseal periprosthetic osteolysis in two of seven Gruen zones associated with eccentric polyethylene wear awaiting metaphyseal bone grafting and cup liner exchange. One stem (0.5%) was revised due to infection. No stem altered in varus or valgus alignment more than two degrees and mean subsidence was 0.1 mm (range: 0 to 2) after a mean of 17.0 years. Five stems (2.4%) required or are awaiting revision surgery. Trabecular orientation and micro-anatomy suggested proximal load-transfer patterns in all except three cases (98.6%). Combined metaphyseal and diaphyseal osseo-integration and bone remodeling were visible in one hundred stems (48%). Diaphyseal stress shielding and cortical thickening were observed in three stems (1.4%). Other radiographic features are discussed in depth. This long-term study of 208 fully HA-coated Corail stems showed highly satisfactory osseo-integration and fixation in 97.6% after a mean of 17.0 years follow-up.

N. Botan B. Fourie S. Scott N. Shaw

The JRI cemented total hip replacement consisted of an acetabulum with a gamma irradiated UHMW polyethylene cup encased in a titanium metal shell, a 32 mm titanium head, and forged titanium alloy stem. Revision of this implant for failure, in particular that of the acetabulum, and the lack of published survivorship prompted a retrospective review of the local series. Data was compiled from theatre log books, patient records and X-rays.

During the period 1989–1997 a single surgeon performed 304 total hip replacements using this JRI prosthesis through an anterior lateral approach. The average age was 70 (48–96), with 186 (61%) female and 85% performed for osteoarthritis. Complete data was available in 236 cases to allow further analysis. The average follow up was 9.3 (1–17) years. During this period 37 hips had to be revised: 28 for a loose acetabulum, both components were loose in 5, and 3 had revision for infection. The mean time to revision was 7.4 (1–17) years.

This data provides a revision rate of at least 16% at ten years. This data does not take potential earlier radiographic failure nor patient function into account. This prosthesis therefore fails to comply with modern benchmarks for survivorship of implants. Furthermore this study highlights the importance of ongoing review of patients who have undergone joint replacement, in particular those with implants that have problems with design, as has been demonstrated in other metal backed components.


Bio-active fixation has increasingly gained acceptance over the last two decades. However extent of the coating is still a subject of debate. We introduced in 1986, the concept of total osteointegration of a tapered stem with the hope that we could achieve durable biological fixation while preserving a normal periprosthetic bone trophicity. Patients from our first clinical series using this stem are now eligible for 18-year follow up. Between July of 1986 and December of 1990 we performed 615 total hip arthroplasties using the Corail stem (DePuy). It is a straight tapered stem totally coated with a 150 μ thick layer of HA following an atmospheric plasma-spray process. The mean age at surgery was 64.5 (range 16 to 95 years) 242 patients are now deceased (39%), 62 (10%) patients are lost to follow-up. The mean follow-up for 243 living patients on file is 17.7years. 89 THAs required component revisions. 72 cup revisions were associated with wear and osteolysis. 8 cups and 4 stems have been revised for aseptic loosening. Owing to the high incidence of wear-related revision, Kaplan-Meïer survivorship at 18-year follow-up, using component revision for any reason as an endpoint, was 80.7±3.3 (95% confidence intervals). In contrast, Corail stem survivorship, using stem removal for any reason as an endpoint, was 95.0%±3.0 at 18-year follow-up, and considering aseptic loosening only, the survival probability of the stem is 98.9%±1.1 at 18 years. Therefore, despite wear and proximal osteolysis the fixation achieved with this totally HA-coated stem remained durable through 18-year follow-up. Regarding the periprosthetic remodelling during this period, modifications of the bone pattern have been strictly limited: slight resorption at the calcar level, absence of cortical hypertrophy, anecdotic significant stress-shielding. The radiological silence is one of the paramount facts demonstrated by this prospective study.

E. Garcia-Rey T. Muñoz J. Montejo J. Martinez

Introduction: Modular metaphyseal-diaphyseal femoral stems are infrequent in primary total hip arthroplasty. We analyse the results of a proximally hydroxyapatite coated anatomic two-piece modular femoral stem over a minimum five years follow-up.

Material and Methods. 94 ESOP (Fournitures Hospitalieres, France) stems are analysed. The mean follow–up was 70.45 + 8.6 months. Patients’ mean age was 65.8 + 9.6 years. Proximal osteopenia and radiographic stem fixation are assessed according to Engh et al.

Results: There were 2 aseptic femoral stem loosenings. There were no cases with thigh pain. Three stems presented subsidence. Mean femoral canal filling was 89% and was related to stem subsidence (p< 0.05). Stable bone fixation was obtained in 83 hips and was related to fluted femora (p< 0.0001). The cumulative probability of not having radiographic loosening was 97.8% (94.8% to 100%). The cumulative probability of not having proximal femoral osteolysis was 86.0% (78.9% to 93.1%), cortical widening 88.1% (81.5% to 94.7%), and proximal osteopenia 94.5% (89.8% to 99.2%).

Conclusions: A cementless two-piece modular hydroxyapatite coated femoral stem provides good clinical results with an absence of pain and excellent radiographic results when there is good adaptation between the metaphyseal part of the stem and the femoral anatomy. This design is an option in femora with good bone quality and especially in tunnel-shaped cases. Femoral osteopenia and cortical widening were infrequent in this series. The modular metaphyseal-diaphyseal junction is not an in vivo problem, contrary to previous reports. A longer follow-up is needed to assess the results of this design.

R. Raman V. Eswaramoorthy D. Dickson P. Angus

Aim: To report the clinical and radiological outcome of consecutive primary hip arthroplasties using the JRI-Furlong Hydroxyapatite ceramic (HAC) coated femoral and acetabular components

Methods: We reviewed 586 consecutive cementless primary THA using HAC coated components in 542 patients, with a minimum 12-year follow-up to 18 years, performed at one institution between 1986 and 1994. Twenty eight (32 THA) were lost prior to 12-year follow-up, leaving 514 patients (554 THA) available for study. Threaded cups were used in 64% and press-fit cups with screws in the rest. Fully HAC coated stems were used in all patients. The clinical outcome was measured using Harris, Charnley and Oxford hip scores. Anterior thigh pain was quantified on a visual analogue scale (VAS) and quality of life using EuroQol EQ-5D. Radiographs were systematically analysed for implant position, loosening, migration, osteolysis and stress shielding. Polythene wear was digitally measured. The radiographic stability of the femoral component was determined by Enghs criteria

Results: The mean age was 75.2 yrs. Dislocation occurred in 12 patients (3 recurrent). Re operations were performed in 11 patients (1.9%). Four acetabular and one stem revisions were performed for aseptic loosening. Other re-operations were for infection (2), periprosthetic fractures (2), cup malposition (1), revision of worn liner (2). The mean Harris and Oxford scores were 89 (79–96) and 18.4 (12–32) respectively. The Charnley score was 5.7 (5–6) for pain, 5.3 (4–6) for movement and 5.4 (4–6) for mobility. Migration of acetabular component was seen in 4 hips. Acetabular radiolucencies were present in 54 hips (9.7%). The mean linear polythene wear was 0.06mm/year. Stable stem by bony ingrowth was identified in all hips excluding one femoral revision case. Mean stem subsidence was 2.2mm (0.30–3.4mm). Radiolucencies were present around 37 (6.6%) stems. Mean EQ- 5D description scores and health thermometer scores were 0.81 (0.71–0.89) and 86 (64–95). With an end point of definite or probable loosening, the probability of survival at 12 years was 96.1% for acetabular and 98.3% for femoral components. Overall survival at 12 years with removal or repeat revision of either component for any reason as the end point was 97.2%.

Conclusion: The results of this study support the continued use of a fully coated prosthesis and documents the durability of the HAC coated components. In our clinical experience, the Furlong prosthesis revealed encouraging radiographic stability over a long term period.

A.J. Tonino B. Grimm B.C. van der Wal I.C. Heyligers

Introduction: Investigating the correlations between bone ongrowth and HA resorption on coated implants is important to understand the contribution of resorbable coatings on implant fixation and periprosthetic bone remodelling. It is only possible histomorphometrically and this study measured bone apposition and residual HA on hip stems of one single design.

Methods: Post-mortem retrievals of 13 ABG-I (Stryker) hip stems from 13 patients (10f, 3m, age: 58–86yrs, uneventful THA, death unrelated to hip diseases). The time from implantation (stem in-vivo) ranged between 3.3 to 11.2yrs.

Three cross sections were cut from the metaphyseal femur and surrounding bone proximal to Gruen zones 2 and 6 (regions with HA coating). The three sections were A (proximal), B (mid-part) and C (distal). Sections were prepared using the Donath technique and then paragon stained for quantitative histomorphometry using an Axioskop microscope (Carl Zeiss, Germany) with image analysing (SAMBA, France).

For each segment the total implant perimeter, percentage of implant perimeter covered by bone and the total percentage of residual HA coating were measured. Bone implant contact was defined as direct ongrowth of bone to the coating or the titanium surface.

Results: HA resorption increased significantly with the time in-vivo as measured by the residual HA (e.g. < 6yrs: Avg.=36.7%, > 6yrs: Avg.=10.1%, p=0.02). This correlation was true for all sections A, B and C (p=0.02–0.03). Beyond 8yrs HA was almost gone.

Bone ongrowth ranged between 18%–56% and was independent of the time in-vivo. Bone ongrowth was most strongly correlated to patient age with younger patients having significantly higher bone ongrowth (p=0.001). Bone ongrowth was correlated with HA-resorption only in the most proximal zone A (p=0.001) with lower ongrowth associated with lower levels of residual HA. However, HA resorption was not significantly correlated with patient age.

HA resorption was significantly higher most proximally with less residual HA (13.0%) than mid-stem (22.6%, p=0.05) and distal (28.1%, p=0.05). Metaphyseal stem level and bone ongrowth were not significantly correlated in this manner.

Discussion: HA resorption increased with implantation time and was nearly completed at 8yrs. As bone ongrowth was independent of time in-vivo and independent of HA resorption on the mid-part and distal coated stem sections there is evidence that long term implant fixation is not diminished while the HA coating is being resorbed.

Bone ongrowth but not HA resorption was strongly correlated to patient age indicating that the bone remodelling process is more affected by individual bone health than it can be stimulated by HA coating.

HA resorption increased significantly from the distal to mid-stem and the most proximal coating level in the same way as stress shielding and thus osteoclastic stimulation goes up.


Osteointegration of HA coated devices is well demonstrated. An abundant experimental material exists, allowing to describe the various properties of HA (early osteointegration, sealing effect, gap healing effect, etc…). Various side-effects have been described (third body wear of HA debris, delamination of the proximal coating etc…). Thus controversy still exists, despite a more and more convincing clinical experience. The role of human retrievals is therefore crucial to determine the exact role of all these parameters in the natural life of the implant throughout the years.

49 human well-functioning explants have been retrieved during systemic autopsies in elderly patients previously operated for a displaced fracture of the neck with a Corail® implant. Delays of implantation vary from 5 days to 10 years. All these specimens have been processed for optical microscopy, electronic microscopy with backscattering. This constitutes the longest report on one single implant and the retrievals are evenly distributed over this ten-year period. Several histomorphometric parameters were measured in the different Gruen’s zones: cortical bone density, cortical bone thickness, density of endosteal bone

3 steps are recognized:

Bone formation around the implant appears early after surgery. Multiple units of bone formation go to coalescence as soon as 6 weeks and develop thereafter, leading to osteointegration.

Bone remodelling reorganizes the architecture of connecting trabeculae according to the mechanical stresses resulting from the presence of the implant. Compression areas are generally the seat of broad and interconnected trabeculae, whereas tensile stresses areas display the presence of long, thin, unconnected and often parallel trabeculae. Very broad and short trabeculae are often seen at the level of the corners.

Coating resorption is seen in every specimen beyond one year of implantation, predominantly in the areas with less bone coverage.

Release of HA particles in the joint cavities was never encountered. Some metallic particles, originating from the femoral ball are commonly seen in the polyethylene. HA particles (presumably scratched off the prosthesis during insertion?...) have never been identified in the heterotopic ossifications.

We conclude that the osteointegration of the Corail stems is a reliable phenomenon with a reproducible sequence of events. It lasts even after the disappearance of the coating in a 5–10 years period. The presence of the stem provokes a remodelling of the cortices but the presence of a total coating and its longer duration at the level of the tip does not induce a disappearance of the proximal bone or a loose of the proximal fixation.

B.J. de Kramer B.C. van der Wal B. Grimm I.C. Heyligers A.J. Tonino

Introduction: In uncemented total hip arthroplasty (THA) stem sizing and stem insertion affect the fit and fill of the prosthesis in the medullary canal. This study investigates how tightness of the stem fit influences bone remodelling and if there is a correlation between radiological and clinical Results: Methods: In a retrospective study a consecutive series of 64 patients following uncemented THA with a proximally coated anatomic stem (ABG-II, Stryker) was followed-up for 5 years using the Merle d’Aubigne (MdA) clinical score. Radiographic analysis of bone remodelling features per Gruen zone (R1 to R7) was performed on AP and lateral x-rays at 5 years. Femoral fit was measured at three levels (proximal, mid-stem, distal) on the direct postop x-ray using the femoral fit ratio (f) of Kim and Kim (tight femoral fit: f≥0.8, non-tight: f< 0.8). The medullary canals were categorised according to Noble (normal, stove pipe, champagne flute). Bone remodelling was compared to literature values of the ABG-I stem and correlated to clinical findings.

Results: The MdA improved from 9.6 pre-op to 17.1 at 5 years with no difference between tight and non-tight implants. Lateral thigh pain (LTP) occurred in 10/64 cases (3 requiring medication). Patients with LTP had significantly lower proximal (0.75 vs 0.80) and distal fit & fill (0.72 vs 0.79. LTP was equally frequent with a normal or varus position.

Proximal bone resorption occurred in 27% (R1) or 34% (R7) which is lower than the values reported for the ABG-I stem (R1: 48%, R7: 45%). Bone resorption was significantly higher with tight than non-tight mid-stem fit (69% vs 27%, p=0.04). The same trend was true for tight distal fit (56% vs 37%).

Cancellous densifications were frequent at mid-stem level (R2: 83%, R6:88%) but much less distally (R3: 44%, R5:25%). No influence of fit & fill was measured.

Cortical densifications were noted in 16% (ABG-I 15%) overall with a higher proportion measured for tight distal fit (25%) than loose distal fit (6%, p=0.07). A similar observation was made for cortical thickening (11% overall, tight:non-tight=16%:6%). Pedestal formation (17% overall) was more likely with a non-tight proximal fit (23% vs 12%) and mid-stem fit (20% vs 8%)

A proximal tight fit was achieved more frequently with normal (55%) and stovepipe femora (50%) than champagne flute femora which had the highest proportion of tight distal fit (85%).

Discussion: At 5 years femoral implant fit influenced bone remodelling reactions which are in agreement with the design philosophy of proximally press-fitting anatomic stems. However, implant fit could not be correlated to clinical outcome yet. This may require a longer follow-up.

As LTP occurred with non-tight fit it seems that elastic mismatch is not the main cause.

Less proximal bone resorption and less distal densifications confirm the design changes from ABG-I to ABG-II.

H. Behensky N. Walochnik C. Bach R. Rosiek P. Winter M. Liebensteiner M. Krismer

Study Design/Objective: Prospective two-leg cohort study on anterior cervical fusion versus cervical arthroplasty with emphasis on clinical outcome measures.

Patients and Methods: Between August 2003 and May 2005 21 consecutive patients underwent anterior cervical fusion with or without anterior decompression with 26 levels fused. Between December 2004 and August 2006 24 patients had cervical arthroplasty with 30 levels replaced. The mean age at operation of the fusion group was 52 years and 5 months (46–69) and for the arthroplasty group 51 years and 2 months (42–62). To establish fusion the Cervios® cage (Synthes) with or without anterior plating was used. In the arthroplasty group the Prodisc C® disc prothesis (Synthes) was used. Contraindication for arthroplasty were osteoporosis, osteopathies, spinal canal stenosis, hypertrophic spondylarthrosis, spondylolisthesis, tumors and privious infection. Both groups were comparable with respect to age and gender, diagnosis, level distribution and preoperative clinical outcome measures (VAS for nack pain and arm pain, neck disability index and SF-36–sub-scores pain, function, vitality).

Results: Postoperatively all of the clinical outcome measures significantly improved in both groups. After three months postoperatively no significant further improvement was evident.

VAS neck pain: Fusion group/arthroplasty group: Preoperatively 6.2/5.9 n.s., 6 weeks 3.5/3.1 n.s., 12 weeks 2.1/1.9 n.s, 1 year 2/2.1 n.s.

VAS arm pain: Fusion group/arthroplasty group: Preoperatively 5.5/5.3 n.s., 6 weeks 2.6/2.4 n.s., 12 weeks 1.7/1.8 n.s, 1 year 2/1.9 n.s.

Neck disability index: Fusion group/arthroplasty group: Preoperatively 43/40 n.s., 6 weeks 28/23 p< 0.05., 12 weeks 18/14 p< 0.05, 1 year 20/15 p< 0.05.

SF-36 subscore pain: Fusion group/arthroplasty group: Preoperatively 36/37 n.s., 6 weeks 42/44 n.s., 12 weeks 52/58 p< 0.05, 1 year 52/60 p< 0.05.

SF-36 subscore function: Fusion group/arthroplasty group: Preoperatively 52/54 n.s., 6 weeks 57/59 n.s., 12 weeks 60/62 n.s, 1 year 64/67 n.s.

SF-36 subscore vitality: Fusion group/arthroplasty group: Preoperatively 42/44 n.s., 6 weeks 45/46 n.s., 12 weeks 50/52 n.s, 1 year 54/56 n.s.

In the fusion group we had 1 recurrent radiculopathy and 1 non union without the need of further intervention. In the arthroplasty group we faced 1 recurrent laryngeus recurrens nerve palsy and 3 spontaneus fusions within 1 year postoperatively, which might not be classified as complication.

Conclusion: Short term outcome after both procedures is excellent in terms of pain relief and function. 10% spontaneus fusion after disc replacement within the first year was evident. In our series we found better results after 3 months to 1 year postoperatively with respect to the neck disability index and SF-36 subscore pain within the arthroplasty group.

R. Kakkar A. Siva Raman A. Bhadra P. Sirigiri A. Rai A. Casey R. Crawford

Introduction: Although there are several accepted methods of surgical treatment for single level cervical radiculopathy, the choice depends on the surgeon’s preference. The techniques may vary in perioperative morbidity, short and long term outcome, but no study so far has analysed their cost-effectiveness. To compare the outcome and cost-effectiveness of four techniques commonly used for degenerative cervical disc pathology.

Methods: We conducted a observational cohort study from two spinal units. Between 1999 and 2004, 60 patients underwent surgery for single level anterior cervical disc pathology. Out of this 30 patients underwent their surgery in centre A the other 30 in centre B. Centre A used two ACDF techniques-group 1- plate and tricortical graft, group 2- plate, cage and bone substitute (BCP granules). Centre B used two other techniques- group 3- cage alone with autologous locally harvested graft, group 4- disc arthroplasty. We had 15 patients in each of the above four groups. Operating time, blood loss, duration of stay, donor site morbidity, analgesia requirements, and total cost incurred per patient were recorded. All patients were followed up at 6 weeks, 3 months, 6 months, 1 year and 2 years. The clinical outcome and pain assessment were done using the SF12 and VAS.

Results: The three Fusion groups had a similar radiological outcome. With appropriate statistical analysis, there were no differences in physical and mental domains of the SF12 or pain scores between the groups. The average operative time in the group 1 was 160 minutes, group 2 was 100 minutes, group 3 was 90 minutes and group 4 was 105 minutes. Average blood loss was minimal in all groups. The average hospital stay was of 5, 2.7, 2.5, 2 days for groups 1–4 respectively. The average total cost per patient in the group 1 (surgery+stay+plate) was £2790, group 2 (surgery+stay+plate+cage+BCP) was £2400, group 3 (surgery+stay+cage) was £1900, and group 4(surgery+stay+disc implant) was £2350.

Conclusion: All the techniques gave similarly satisfactory clinical outcomes but using cages alone could be more cost-effective than using iliac crest auto-graft for fusion. The disc arthroplasty was comparable to cage with bone substitute and plate in terms of outcome and may giev the surgeon an alternative choice in patients who are not keen on/ unfit for fusion.

D. Daentzer S. Asamoto D. Böker

Introduction: Many different techniques exist for cervical interbody fusion after discectomy for soft and hard disc prolapses. The six years clinical and radiological results and the complications with a hydroxy-apatite ceramic (hac)-titanium implant are presented.

Methods: Between 1/1995 and 12/2000 a titanium implant coated with hydroxy-apatite ceramic (hac) has been used for ventral cervical interbody fusion after discectomy in 596 patients with soft and hard disc prolapses who were operated in 670 levels. There were 333 male and 263 female patients. The mean age was 48.2 years. Clinical and radiological follow-up studies were performed direct after operation and 6 weeks, 6 months and 1 year later with an average follow-up of 14 months. The functional outcome was assessed according to Odom’s score, and the neurological outcome according to Kadoya’s score.

Results: 93.2 % of the patients had a good to excellent result according to Odom’s score at follow-up whereas the neurological findings showed improvement in 71.2 % and no change in 27.9 %. After 6 months a good bony fusion could be seen around 91.2 % of the implants, and after 12 months around 95.7 %. 1,7 % of the operated patients developed a recurrent laryngeal nerve injury. Three implants broke into the adjacent vertebral endplate. Six patients had a second operation because of a dislocated cage. An adjacent segment pathology occured in 25 patients (4.2 %), of whom 15 patients had a second operation.

Conclusions: With the use of this hydroxy-apatite ceramic (hac)-titanium implant we get an immediate postoperative stability of the cervical spine without the need of any orthosis. Harvesting of bone grafts is unnecessary which reduces operation time and eliminates donor site complications. The clinical and radiological are good and comparable to other fusion techniques in the cervical spine and the complication rate is low. If the number of adjacent segment pathology can be reduced with total disc arthroplasty has to be clarified in further comparable studies.

S. BHAGAT J. Modi D. Pillai H. Bhalodiya

Background: Smaller versions of threaded lumbar cages were developed for cervical spine to obviate the need for allograft, iliac autograft use and to provide initial stability before fusion. Clinical trials of threaded cervical fusion cages have shown higher fusion rates and lower rates of graft-donor site complications.

Study design/Aims: Prospective. Radiological and clinical outcomes of an age, sex and diagnosis matched patient population who underwent cervical fusion with (A) BAK/C cages filled with autograft reamings (Center-pulse Spine-tech Inc., Minneapolis, MN) (N=50) were compared with (B) Anterior cervical decompression and fusion (ACDF, N=50).

Methods: Patients with symptomatic cervical discogenic radiculopathy were treated with either anterior cervical discectomy with uninstrumented bone-only fusion (ACDF) or BAK/C fusion cage(s). Independent radiographic assessment of fusion was made and patient-based outcome was assessed by a Short Form (SF)-36 Health Status Questionnaire. All patients had minimum follow up of at least 2 years.

Results: Similar outcomes were noted for duration of surgery, hospital stay, improvements in neck pain and radicular pain in the affected limb, improvements in the SF-36 Physical Component subscale and Mental Component subscale, and the patients’ perception of overall surgical outcome. Symptom improvements were maintained at 2 years. Iliac crest harvesting was carried out as a standard procedure in all cases of ACDF whereas only 2 cases in BAK/C group required the same. Average operative time of 115 minutes and 145 minutes, blood loss of 110ml and 175ml and hospital stay of 1.5 and 3.5 days were noted for BAK/C and ACDF groups respectively. Successful fusion was achieved in 49 cases in BAK/C and 46 patients in ACDF group. None of the patients in the BAK/C group had reappearance of symptoms while 3 patients in ACDF group had developed symptomatic adjacent level disc disease. The complication rate for the ACDF group was 9% compared with an overall complication rate of 3% with BAK/C. Complications that necessitated a second operative procedure included

Graft dislodgement (N=3) and

Cage subsidence, both requiring re-operation in the form of ACDF with plate supplementation.

Conclusions: These results demonstrate that outcomes after a cervical fusion procedure with a threaded cage are the same as those of a conventional uninstrumented bone-only anterior discectomy and fusion with a low risk of complications, less operative time and rare need for autogenous bone graft harvest.

M. Elbel C. Dehner L. Kinzl M. Kramer

Introduction: After whiplash injuries the majority of patients complain of pain, muscular dysfunctions and restricted movement of the cervical spine, however, the cause of these symptoms cannot be diagnosed.

Against this background, the hypothesis is formulated that functional disturbances in the form of pathological activities of the neck muscles occur as a result of a whiplash injury of the cervical spine. These pathological muscle activities can be demonstrated electromyographically and differ from the patterns of activity of healthy subjects.

Study Objective: Thus, the aim of this study was to establish an electromyographical method for the diagnosis of functional disturbances of the neck muscles after whiplash injuries of the cervical spine.

Material/Method: Primarily, an intramuscular recording of the electromyographical activity of the semispinalis capitis muscle was performed during flexion/extension and axial rotation in 46 patients with chronic symptoms after a whiplash injury of the cervical spine (QTF grade II) and 29 healthy subjects. The movement was controlled with techniques of virtual reality. The subject is immersed into a virtual outer space environment with a head-mounted display (HMD). In this virtual scene, the patient follows paths of motion of a signal (globe) with his/her gaze.

A subsequent study was conducted to validate the results that had been obtained. For this purpose, the electromyographical activity of the semispinalis capitis muscle was recorded in another subject group (n=20) and patients with acute symptoms as a result of a whiplash injury of the cervical spine (QTF grade II) (n=35).

Results: Compared to the physiological muscle activities that were established in the first subject group, changes could be observed in the chronic patient group.

Subjects in our study, for instance, show a decrease in electrical activity during flexion and the resulting stretching of the semispinalis capitis muscle, while the same movement causes an increase in activity in patients. On the basis of these differences, 93 % of subjects (specificity) and 83 % of patients (sensitivity) could be classified correctly with a discriminance analysis.

In the second study, the specificity was 88 % while a sensitivity of 86 % was determined in the acute patient population.

Conclusion: The results of these investigations enable a highly specific and sensitive diagnosis of muscular dysfunctions on the basis of the intramuscular recordings of the electromyographical patterns of activity of the semispinalis capitis muscle.

B.J. Lankester H.L. Cottam V. Pinskerova J.D. Eldridge M.A. Freeman

Introduction: The medial tibial plateau is composed of two relatively flat facets. An anterior upward sloping “extension facet” (EF) articulates with the medial femoral condyle from 0 to 20–the stance phase of gait (in Man but not in other mammals). Anatomical variation in this area might be responsible for antero-medial osteoarthritis (AMOA).

This paper reports the angle between the EF and the horizontal (the extension facet angle- EFA) in normal knees and in knees with early AMOA.

Method: MRI reports were searched to identify patients with acute rupture of the ACL on the assumption that they had anatomically normal tibiae (46 males and 18 females) and patients with MRI evidence of early AMOA without bone loss (11 males and 9 females).

A sagittal image at the midpoint of the femoral condyle was used to determine the EFA.

Results: The EFA in normal tibiae is 14 +/− 5 (range 3–25). The angle is unrelated to age. The EFA in individuals with early AMOA is 19 +/− 4 (range 13–26). The difference is significant (p< 0.001).

Discussion: There is a wide variation in the EFA in normal knees which is unrelated to age.

There is an association between an increased EFA (ie a steeper EF) and MRI evidence of AMOA. Although a causal link is not proven, we speculate that a steeper angle increases the duration of loading on the EF in stance and tibio-femoral interface shear. This may initiate cartilage breakdown.

A.K. bhadra A.S. Raman A. Rai A.T. Casey R.J. Crawford

AIM: To compare the outcomes between two different surgical techniques for cervical myelopathy (skip laminectomy vs laminoplasty).

METHODS: Cervical skip laminectomy is a new technique described by Japanese surgeons in 2000. The advantage of this procedure over the other conventional techniques is it addresses multilevel problem in a least traumatic way without need for instrumentation.

We are comparing the above two techniques with 25 patients in each group operated by 3 surgeons. The first group had conventional laminoplasty and the second group underwent the skip laminectomy. The groups were comparable in age, sex, pathology and clinical presentation. Both these group had clinical outcome measurements using SF 12 questionnaires, pre and postoperative clinical assessment with standard tools performed by independent surgeon and a specialist spinal physiotherapist. We also routinely performed pre and postoperative MRI scans to assess the adequacy of decompression.

RESULTS & CONCLUSION: There was no significant difference in the outcome of these patients in terms of the operative technique, hospital stay, clinical and radiological outcome. However skip laminectomy is relatively a easier procedure to perform, while the laminoplasty does need instrumentation.

M. Kramer C. Dehner M. Elbel L. Kinzl

Background: In a car-to-car collision, an adequate force has to be exerted to produce an injury of the cervical spine. This force is often described with the parameter delta-V. Limits for delta-V were defined for rear-end, frontal and side collisions on the basis of dummy experiments and volunteer crash tests under laboratory conditions, and then transformed for the road accident situation. According to this definition, an injury in a rear-end or side collision is unlikely at delta-V< 10km/h and probable at delta-V> 15km/h. For frontal collisions, the values are 20 km/h and 30km/h. To this day, there is no data to confirm these limits in the actual road accident situation.

Objective: Our objective was to compare clinical data and data from accident analyses of individuals after actual car-to-car collisions in a prospective study. We intended to check the validity of the delta-V limits on the basis of this data.

Methods: 57 individuals (25 males/32 females) were included in the study. The delta-V was calculated by a technical expert on the basis of photographs of the two cars involved. The individuals who had been in an accident were evaluated with regard to their history. Those reporting symptoms underwent a radiological and clinical examination.

Results: Rear-end collisions (n=21): The median delta-V for rear-end collisions is 13 km/h (min=3 km/h; max=58 km/h). 7 individuals reported symptoms. Both patients had delta-V values< 9km/h. Delta–V 10km/h.

Frontal collisions (n=13): The median delta-V for frontal collisions is 24 km/h (min=8 km/h; max=50 km/h). 4 individuals reported symptoms. Under delta-V 20, one individual had a fractured cervical vertebra (QTF IV).

Side collisions (n=19): The median delta-V for side collisions is 12 km/h (min=4 km/h; max=59,3 km/h). 9 individuals reported symptoms. Under delta-V 10 km/h, two patients had symptoms (QTF II and QTF IV (fracture).

Conclusions: The existing limits for delta-V cannot be transferred without reservation from the laboratory test situation to the actual road accident situation. Injuries and even fractures of the cervical spine can occur at a delta-V < 10km/h, particularly with side collisions. At the same time, delta-V values > 15km/h do not necessarily result in an injury of the cervical spine.

A.F. Mavrogenis P. Liantis P. Kontovazenitis P.J. Papagelopoulos D.S. Korres

The purpose of this study was to propose a new classification based on the structural, anatomical and biomechanical properties of the odontoid process, to evaluate the outcome and to suggest the adequate treatment in relation to the specific fracture type.

The files of 97 patients with odontoid process fractures admitted to our institution were reviewed. The external and internal anatomy of the axis has been studied. The fractures were classified according to the proposed new classification. The method was tested for reliability and validity. Mean follow-up was 14 years.

Intraobserver and interobserver agreement was excellent with intraclass correlation coefficients at levels of 0.98 and 0.85 respectively. Four types of odontoid process fractures are distinguished; type A fractures are avulsion fractures involving the tip of the odontoid; type B fractures are fractures of the neck between the lower edge of the transverse ligament and the line connecting the medial corners of the upper articular facets of the axis; type C fractures involve the area between the previously mentioned line and the base of the odontoid process (type C1) or extend to the body of the axis (type C2); type D fractures are complex fractures involving more than one level of the odontoid process.

Classification of odontoid process fractures has to be reconsidered as novel imaging technology has shown new patterns of fractures. Computed tomography scan with image reconstruction is mandatory. The analysis of the imaging data in the present study justifies the new classification.

M. Akbar G. Balean T.M. Seyler H.J. Gerner M. Loew

Introduction: Musculoskeletal injuries of the shoulder in paraplegic patients can result from overuse and/or incorrect use of wheelchairs. With improved long-term survival of these patients who exclusively depend on their upper extremities for weight-bearing activities such as transfers and wheelchair propulsion, they are particularly susceptible for shoulder pathologies. The purpose of this study was to compare the functional and structural changes in weight-bearing shoulders of paraplegic patients who are wheelchair dependent for more than 30 years with able-bodied volunteers.

Methods: This was a randomized study with 80 (160 shoulders) patients who had been paraplegic and wheelchair dependent for a mean of 33 years. These patients were matched for gender, age, occupation, and hobbies to a group of 80 (160 shoulders) able-bodied volunteers. The mean age for the paraplegic patients was 54 years and 51 years for the matched volunteers. Shoulders from both groups were prospectively evaluated using MRI. All films were analyzed by two board-certified radiologists who were blinded to the study. Prospectively collected outcome measures included a standardized clinical examination protocol, the Constant score, and visual analog scale (VAS) pain scores.

Results: The shoulder function according to the Constant score was significantly worse in paraplegic patients compared to able-bodied volunteers (p< 0.001). Similarly, the VAS scores were significant greater in the paraplegic patients (three-fold higher pain intensity, p< 0.001). Comparison of the MRI films of the paraplegic patients and the volunteers revealed the following significant differences: rotator cuff tears 67% (108/160) vs 5.6% (9/160); tendonitis 50% (80/160) vs 23% (37/160); tendonitis of the long head of the biceps 25% (40/160) vs 3.7% (6/160); rupture of the long head of the biceps 10% (16/160) vs 2.5% (4/160); subacromial subdeltoid bursitis 71% (113/160) vs 34% (55/160); acromioclavicular osteoarthritis 33% (53/160) vs 15% (24/160); and glenohumeral osteoarthritis 15% (24/160) vs 8% (13/160).

Conclusion: This is the first study comparing the long-term effect on shoulder pathologies of paraplegic wheelchair users to a cohort of able-bodied volunteers. The complications of weight-bearing activities in these patients require appropriate prevention including wheelchair and/or home modification, physical therapy, pharmacological pain management, surgical intervention, and patient education.

T. Mumme R. Marx R. Mueller-Rath S. Andereya D. Wirtz

Introduction: Aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard the adhesion strength of the metal-bone cement interface is of major interest.

Material und Methods: Cemented tibial components coated with a silica/silane interlayer system (n=8) were dynamically loaded within a knee-simulator (DIN ISO 14243). After loading, the components were cut by “high pressure water jet technique” (Fraunhofer Institute for Production Technology, Aachen, Germany) into 10 slices (thickness 5 mm each) parallel to the shaft axis according to a standardised protocol. To evaluate the metal-bone cement interface with regard to gaps and cement failure, the tibial slices were analysed by light and fluorescent microscopy. These data were matched with uncoated components (n=8).

Results: The coated tibial components yielded a significant reduction of gaps in the metal-bone cement interface (p < 0.05) as well as a highly significant reduction of cement mantle failure (p < 0.001).

Conclusion: With the help of the silica/silane coating, gaps in the metal-bone cement interface with consecutive early cement mantle failure due to mechanical overstressing can be significantly reduced.

A. Martin M. Prenn O. Wohlgenannt A. von Strempel

Introduction: The benefits of postoperative wound drainage in patients with total knee arthroplasty (TKA) with regards to mobilisation and wound healing were studied. We wanted to determine the efficacy of an autologous blood retransfusion system.

Materials and Methods: 150 patients with TKA were divided into three groups of 50 patients:

A) Three wound drainages with an autotransfusion system and suction;

B) no wound drainage;

C) one intraarticular wound drainage without suction.

Haemoglobin values, blood transfusion requirements, blood loss, postoperative range of motion, knee society score and rate of complications were observed and recorded. All patients were operated without tourniques for lower blood loss during total knee replacement.

Results: In the group of patients with wound drainage and a retransfusion system the requirement of postoperative additional blood transfusion was not significantly less than in the group without wound drainage. Group A had the most blood loss of all. The group without wound drainage had more haematoma and wound healing complications. Best results were observed within the group with one intraarticular drainage without suction. The rate of complications was not increased and the blood transfusion requirements were the lowest.

Conclusion: This study shows that total knee replacement involving one intraarticular wound drainage without suction attains the best results. During the last four years we used this wound drainage technique in 787 TKAs and can confirm all findings of this study.

V.J. Luque J.C. Roa M.T. Porcel M. Quiles

Total knee arthroplasty had been reported to present similar amount of blood loss in external and hidden form. We studied whether lateral patellar release made any differences on both forms of blood loss.

Material and methods: We studied 91 patients (83 women an 8 men) undergoing primary unilateral total knee arthroplasty cemented posterior stabilised with patellar substitution, in 40 lateral patellar release were performed. Surgery is performed under tourniquet. The blood drain was recorded. We assumed that blood volume on the fourth postoperative day was the same as before surgery. Blood volume was estimated taking sex, body mass and height into account. Haemoglobin was recorded on preoperative and four days postoperative.

Results: We found more external blood loss in patients without lateral patellar release (p< 0,05) but no statistical differences in total and hidden blood loss. The amount of hidden blood in both groups were more than twice (975 mL) the external blood loss (443 mL). No relationship was found between body mass and any type of blood loss.

Conclusions: Lateral patellar release made no difference in the amount of total blood loss. In total knee arthroplasty hidden blood loss doubled external blood loss.

N. Moreno M. De la Torre R. Luis

Introduction: Obesity is a risk factor to develope knee OA. Patients who are obese often consider their disabling joint disease as a cause for their increased weight. The purpose of this study is to evaluate the changes of weigth and BMI in obese patients after TKA

Methods: 102 obese patients who underwent TKA between January 2002 and December 2003 were evaluated. They were followed for a mean duration of 35 months. Data about age, height, weight, BMI, hypertension, diabetes, NSAIDs and crutches were collected preoperative and at the end of follow-up. Statystical analysis was done using SPSSv11.5.

Results: Mean age was 69.8 y.o.. The average height was 157 cm. 24 were men and 78 women. Mean preoperative weight was 86.7 Kgs and at the end of follow-up was 87.3. BMI rose from 35.1 to 35.3. 90% recognized a better quality of life. 12.2% have a better control of their hypertension.30% needs NSAIDs and 4% uses crutches.

Conclusions: Obesity leads to an important number of Total Joint Replacement, specially TKA. Apparently it haven’t a worse outcome. Patients doesn’t loose weight after TKA, someones gain it. Knee OA can’t be considered as a cause of overweight.Obesity should be treated as an independent disease.

F. Thorey C. Stukenborg-Colsman G. von Lewinski C. Wirth H. Windhagen

Introduction: Besides other techniques to reduce blood loss, the use of pneumatic tourniquet is commonly accepted in total knee arthroplasty (TKA). Furthermore it is used to maintain a clean and dry operative field to improve visualization, to use a better cementing technique, and to reduce operating time. The time of tourniquet release is discussed controversially in literature. However, there are only a few prospective randomised studies that compared the effect of timing of tourniquet release in cementless or cemented TKA. To our knowledge, this is the first study that investigated the influence of tourniquet release on blood loss in a randomized prospective study in simultaneous bilateral cemented TKA.

Methods: 20 patients (40 knees) underwent simultaneous bilateral cemented TKA with the cemented Triathlon Knee System (Stryker) between February and May 2006. The mean age of the patients was 67 years (67+/−11 years). 7 males and 13 females were treated with TKA (mean tourniquet pressure: 282.5+/−33.5 mm Hg). In 20 patients one knee was operated with tourniquet release and hemostasis before wound closure (“Technique A”), and the other knee with tourniquet release after wound closure and pressure dressing (“Technique B”). To determine the order of tourniquet release technique in simultaneous bilateral TKA, the patients were randomized in two groups: “Group A” (20 knees) first knee with tourniquet release and hemostasis before wound closure, and “Group B” (20 knees) second knee with tourniquet release and hemostasis before wound closure. The patients were given low molecular weight heparin and a leg dressing to prevent deep vein thrombosis. The blood loss was monitored two days after surgery till removal of the wound drains.

Results: We found no significant difference in total blood loss between “Technique A” (753+/−390 ml) and “Technique B” (760+/−343 ml) (p=.930). Furthermore there was no significant difference in total blood loss between both techniques after randomizing in “Group A” (“Technique A” 653+/−398 ml; “Technique B” 686+/−267 ml; p=.751) and “Group B” (“Technique A” 854+/−374 ml; “Technique B” 834+/−406 ml; p=.861). However, the operating time showed a significant difference between “Technique A” (58+/−18 minutes) and “Technique B” (51+/−17 minutes) (p=.035).

Discussion: In this study we compared the effect of timing of tourniquet release on perioperative blood loss in a randomized prospective study in simultaneous bilateral cemented TKA. Our results showed no significant difference of blood loss but a significant difference of operation time. Therefore, we recommend a tourniquet release after wound closure to reduce operating time and to minimize the risk of peri- and postoperative complications at approximately similarly blood loss between both techniques.

G.A. Medalla P. Moonot U. Okonkwo Y. Kalairajah R.E. Field

INTRODUCTION: The American Knee Society score (AKSS) and the Oxford Knee score (OKS) are widely used health outcome measures for total knee replacements. The AKSS is a surgeon-assessed, variable weighted knee score. The OKS is a patient assessed equally weighted score. Our aim was to evaluate whether patient self assessment is a viable alternative to clinical review and whether it can provide enough information to identify which patient would require a clinic visit.

As there had been no previous studies correlating the two scoring systems, we investigated whether a correlation exists between the two scores at 2, 5 and 10 year periods. A correlation would allow us to determine what OKS value would achieve 90% sensitivity in identifying patients requiring clinical review at the above time points. This strategy would reduce the number of clinical visits required and its associated cost.

METHODS: We reviewed the data gathered prospectively from January 2000 to April 2006. All patients were part of an ongoing multi-surgeon single institution Knee Arthroplasty Outcome Programme. Preoperative, 2, 5 and 10 year post-operative OKS and AKSS were gathered from different cohorts. This method of comparison has been validated by previous publications. The scores were then analyzed using the Pearson correlation and linear regression. Different OKS values were analyzed for sensitivity and specificity.

RESULTS: 175 patients completed both the OKS and AKSS questionnaires preoperatively. 312 completed both scores at 2 years; 124 at 5 years and 57 patients at 10 years. The mean OKS, and the two AKSS components, the Knee score and Functional score improved significantly 2 years postoperatively when compared to their preoperative values. The Functional score deteriorated significantly from 5 to 10 years (p< 0.0001). There was good correlation between the OKS and the Knee score and Functional score at 2 years and a moderate correlation at 5 to 10 years. OKS > 24 showed more than 90 % sensitivity in identifying poor Knee scores in the 2, 5 and 10 year periods.

CONCLUSION: In this study, the good correlation of OKS and AKSS at 2-years suggests that postal Oxford questionnaire is sufficient in following up patients in the short term after total knee replacement. However, the moderate correlation at 5 and 10 years suggests that clinical evaluation is necessary.

We recommend that at 2 years, all patients complete an OKS questionnaire and if this is above 24, a clinical evaluation maybe required. Using this OKS value as a screening technique would allow a reduction of up to 50% in clinic visits and outpatient costs at the 2 year follow-up. This reduction is not as great at the 5 and 10 year periods. At these time periods, we recommend a clinical follow-up.

R. Trappler E. Smith G. Goldberg J. Parvizi W.J. Hozack

INTRODUCTION: Range of motion following TKA is a commonly assessed and important outcome parameter. The reported knee ROM is often measured using manual goniometers. The accuracy of goniometer in measuring ROM of the knee is not known. We compared the knee ROM measured with a manual goniometer and compared that to measurements obtained from computer assisted navigation system.

METHODS: This prospective ongoing study has so far recruited 60 patients (71 knees) undergoing TKA by a single surgeon. Measurements of the ROM were performed intraoperatively using a 14 inch 360° Nexgen Baseline® goniometer, validated by physical therapists, and the Stryker knee navigation system. Consistent anatomical landmarks were used to obtain flexion and extension measurements. Each goniometer and navigation measurement was performed twice by the same reader.

RESULTS: Goniometer was more inaccurate in measuring the knee ROM than the navigation. There was a 5.07° difference between two measurements obtained with the goniometer compared to a mean discrepancy of 1.15° using the navigation system. Further, the ROM measured by navigation was on average 13.9° larger than that measured by the goniometer. BMI affected the ROM recording obtained by both the goniometer and the navigation system.

DISCUSSION AND CONCLUSION: This study indicates that goniometer is not an accurate tool for measurements of knee ROM as there is a marked discrepancy between two goniometer readings. The navigation system seemed to produce more consistent, but markedly higher, readings than a manual goniometer. Reported results on knee ROM in the literature need to be interpreted with caution and scrutinized for potential inaccuracy of the measuring tool.

P. Hamilton M. Edwards Q. Bismil S. Bendall D. Ricketts

Introduction: Since the first meeting in 1875, and the subsequent introduction of the concept of evidence based medicine in the 1990s, the journal club has become an integral part of keeping abreast with current literature.

There is no study assessing orthopaedic journal clubs amongst training programs across the UK. This study had two aims: the first was to determine whether journal clubs still play an important part in orthopaedic training programs, the second was to evaluate the frequency, format and goals of journal clubs conducted in orthopaedic training programs in the UK.

Method: We surveyed fifty seven hospitals across the UK. This included hospitals from all the orthopaedic teaching regions of which twelve were teaching hospitals and forty five district general hospitals.

Results: A total of 57 hospitals were surveyed. Of these hospitals 28/57(49%) had a journal club programme in place. On average journals clubs were undertaken once a month and lasted about 1 hour. Most occurred during the working day and were chaired by a consultant. Specialist registrars presented the vast majority of papers (average of 1.9 each per session), with the JBJS Br being the most widely used journal (100% of journal clubs).

Of the twelve teaching hospitals questioned, five (42%) had journal clubs, and twenty three of the forty five (51%) district general hospitals had journal clubs. The average number of articles critically appraised by trainees who attended journal clubs was 5 (0–15) compared to 3 (0–18) in those not attending a journal club.

When asked whether there was any alternative way in which a trainee might otherwise learn how to critically appraise an article, fourteen suggested online journal forums and eighteen suggested self-directed learning or personal study.

Although only 49% of hospital had journal clubs, 88% of trainees believed that it formed a valuable part of training and 56% thought it should be compulsory.

Discussion: This study shows that journal clubs occur in around half of the orthopaedic departments surveyed across the country. This is despite the importance trainees’ associate with journal clubs being part of their training.

In contrast, studies from North America show that a regular journal club occurs in 99% of residency programs.

It may therefore be suggested that for those trainees who do not attend a journal club, an alternative method to learning the skills of critical appraisement may have to be sort. One suggested modality is through on-line journal clubs or forums within regions which trainees may be encouraged to undertake from their regional directors.

L. de Palma M. marinelli M. pavan A. orazi

Introduction: Pathological conditions, which determine human atrophy, are numerouses and heterogeneous.

Experimental studies prove that these different pathological conditions use common enzymatic pathways leading muscle atrophy. In every catabolic conditions where there is proteolyses’s increase, this one happens in association with up-regulation of two specific genes of skeletal muscle atrophy. These genes, MuRf1 (muscle ring finger-1) and MAFbx (muscle atrophy F-box), encode ubiquitin ligases. These ligases bind and mediate ubiquitination of myofibrillar proteins for subsequent degradation during muscle atrophy.

The aim of our study is to obtain a better understanding of human muscle physiopathology in atrophy by use of histochemistry and immunolocalisation of MuRF-1 and MAFbx.

Patients and Methods: 15 patients, amputated at third distal or proximal leg because of different acute or chronic pathology, were divided in two group. Group A: 12 elderly patients (mean age 72 years) amputated for vascular diseases (8) and complication of a diabetic foot (4). Group B: 3 young patients involved in car accident (mean age 25) amputated for limb’s acute arterial insufficiency. Gastrocnemius muscle biopsy specimens were obtained for all the patients, after that the informed consent was obtain, for histochemical (haematossilineosin), and immunohistochemical (anti- MuRf1, anti- MAFbx) analysis.

Results: Histochemistry: Group A: skeletal muscle showed a decrease in fiber size in cross-sectional area and fiber length with adipose tissue. Group B: light skeletal muscle structural alteration. Immuno-histochemistry: in group A, in muscular drawings, polyclonal antibodies direct against MuRf1 and MAFbx had stained muscle biopsy specimens. Muscle fiber cells showed MuRf1 and MAFbx subsarcolemmatic immunoreactivity and weakly immunoreactivity of the extracellular matrix. We noticed no positivity to anti- MuRf1 and anti- MAFbx less in sections from group B muscle biopsy specimens and in sections in which were present tissue muscle degeneration with replacement of adipose tissue.

Conclusion: The pathological results supported the concept that MuRf1 and MAFbx appeared to be regulatory peptide in cellular pathology that conduce to muscular atrophy. Our data support the hypothesis that different pathological conditions use common enzymatic pathways leading muscle atrophy.

The demonstration that the muscle-specific proteins MAFbx and MuRF1 are upregulated in multiple pathological conditions of skeletal muscle atrophy it is critical to continue studying the cellular pathways to discover promising targets for the development of effective new treatments for skeletal muscle disease.

A. Khurana S. Kadambande R. Kulkarni

Introduction: Complex fractures and singular acute orthopaedic admissions in an individual hospital form only a small proportion of admissions. An average orthopaedic surgeon does not gain and maintain enough experience to provide proficient care. Referral with in the department to a sub-specialist for that anatomical region is forming a norm. We studied the practice in our department to assess how much specialist care we provide.

Materials & Methods: Prospective study over four month’s period with specialist referrals reported by teams and Trauma Fellow. We observed the time spent before making the referrals and that taken by specialists in carrying out management. The spectrum of investigations by various specialist teams was also noted. Number of referrals made to each sub speciality was observed.

Results: Of a total of 836 acute admissions in the department over this four months period, 98 (11.7%) were referred to sub-specialists. Referrals were made on an average of 1.8 days after admission and were seen by the specialist after another 2.1 days. Average time to surgery was 4.7 days after referral. Special Imaging investigations were performed in 84 (86%) patients of whom 31 had been organised before the referral was made. 81 (82%) patients were operated by the specialist teams while rest underwent conservative treatment.

Discussion: With the changing structure and decreasing duration of higher specialist training, expertise in complex trauma is expected to be limited to the anatomical region of surgeons’ interest. Specialist management provides better patient care with improved satisfaction.

Conclusion: In the modern orthopaedic practice with intensive but limited expertise, specialist referrals are the acceptable solution both to the patient and the provider. This should be encouraged. Specialists should provide appropriate investigation and referral protocols.

D. Nicoll H. Mahayni D. Rowley

This study was carried out to evaluate the impact of Socio-Economic Status (SES) and the influence of geographic access to health services on the possible outcomes of total knee replacement (TKR).

Data on 345 patients with one year follow-up were collected from the database of the orthopaedic department. TKR outcomes were assessed according to Knee Society Score (KSS). A postcode was assigned to each patient depending on the residential area and data from the last census was used to calculate Scottish Index of Multiple Deprivation Score (SIMD) and its rating score for geographic access to health services.

The results show that the SES and the geographic access to medical services have significant impact on Function Scores but do not influence Knee Scores.

Patients living in the least deprived regions had a better post-operative Function Scores compared to those living in more deprived regions with differences of up to 13 points between groups (p< 0.001). Similarly the improvement in Function Scores was dependant on deprivation score. (p=0.015). Pre-operative Knee Score, post-operative Knee Score and improvement in Knee Scores were not influenced by deprivation score.

Patients living in rural regions had better post-operative Function Scores and greater improvements in Function Score compared to urban dweller patients (p≤0.011) with differences of up to 17 points. The Knee Score was not influenced by these variables.

These results suggest that SES and the region of residence should be considered when assessing the outcomes of TKR.

S. Bahari B. Lenehan J. McElwain

Introduction: This study was performed to review the changing patterns of trauma admissions in Ireland over 5 years (1999–2005).

Materials and Methods: A review of prospectively collected admission data of trauma patients admitted to the Adelaide & Meath Hospital (AMNCH). Dublin, Ireland, during 2005. Data obtained from Hospital In Patient Enquiry (HIPE) system. A comparison is made similar data from 1999. Demographic data, mode of presentations, type of injuries, time of injury and place of injury were recorded. Injury severity was defined using the Injury Severity Score (ISS).

Results: 23% increase in number of admission in 5 years period. Mean age of admission reduced from 35 (1999) to 32 (2005). 67% of admission occurred outside normal office hours (9am–5pm). Commonest mode of injury was road traffic accident (RTA) in 1999 and sports related injury in 2005. Work related trauma increases by 40% and assault increases by 35% from 1999 to 2005. High energy trauma cases reduce by 50% but open fracture cases double in 5 years. Mean overall ISS score was 56. 7(1999) decreased to 45.9 (2006).

Conclusion: These changes cause significant impact on the health system. Increase in facilities for management of trauma is essential as this trend is more likely to continue.

S. Juenemann C. Hasler R. Brunner

Purpose: X-Rays are presented on CD’s in a digital format with increasing frequency. The impression is that this technique requires more time to present a given x-ray compared to conventional pictures.

Methods: Time was measured for 6 orthopaedic residents presenting the most recent ap-view out of a given set. Ten sets of 6 x-rays for each case were saved in the conventional and digital format each. The order was randomised. As a precondition the computer was on and the same viewer software was used for all digital sets. The results were compared using a non linked student’s t-test (significance level p=0,05).

Results: Presentation of conventional x-rays required 21 sec (+− 7,46), of digital x-rays 90 sec (+− 27,56) respectively (p< 0,001).

Conclusions: In spite of ideal conditions digital x-rays on CD need significant more time in the orthopaedic clinic. In major centres patients present with different software and software in other languages which increase the required time even furhter. This latter problem will be assessed in another study.

Significance: This increase of preparation time used by a highly qualified staff member has implications on economics and logistics.

A. Martin O. Caglar M. Müller V. Senner M.B. Sheinkop M.A. Wimmer

Aim: Cycling is a common activity after TKA and it has been shown that up to 50 % of the TKA patients are riding a bike and 25 % think that cycling has an important place in their life. The specific contact mechanics of tibiofemoral joint is well known during walking, however, there is little data during cycling for TKA patients. The purpose of this study was to determine the tibiofemoral contact mechanics during cycling for TKA patients.

Methods: We recruited 10 patients implanted with a mobile bearing and 10 patients with a fixed bearing posterior stabilized prosthesis. An age-matched, asymptomatic control group consisted of 10 subjects. The patients were physically examined, and WOMAC index and knee society score were taken. Motion analysis was performed using a retroreflective marker based technique called “PCT”. Forces and moments during cycling were recorded with load cells at the crank shafts of the bike. Motion and load data were synchronized.

Results: Resultant pedal forces showed no significant differences between study groups but the generated impulse was higher in the mobile bearing group. Patients with contra-lateral osteoarthritis showed higher forces and impulse at the operated leg. The motion analysis showed the following mean values ±SD for TKA patients/Normals: maximum flexion angle 132.5° ±16.0°/131.5° ±18.3°, minimum flexion angle 41.4° ±12.0°/40.3° ±15.7°, range of rotation in transversal plane 12.6° ±4.7°/9.9° ±3.6° and range of anterior-posterior translation 5.3 mm ±5.1 mm/2.7 mm ±0.4 mm. There were no significant differences between study groups.

Discussion: In this study, force and impulse of TKA patients with contemporary prostheses were comparable to healthy subjects indicating functional restoration of the joint. Contralateral osteoarthritis may cause higher forces at the operated leg and thus, relatively higher stresses at the artificial articulation.

As expected, the generated forces at the bike pedal were low (20–25% body-weight) calling for little muscle activity and low compressive joint forces. However, with a mean maximum flexion angle of 131.5°, the observed motion ranges were higher than expected. Prostheses not designed for high flexion activities could lose tibio-femoral contact during cycling with detrimental effects on wear. Still, the measured range of rotation in the transverse plane indicates that despite its posterior-stabilized design rotation is taking place with approximately the same amount as it occurs in normal subjects. This may have detrimental effects on the post at the tibial plateau and could explain the previously observed rotational damage patterns on retrieved posterior stabilized TKA specimens.

Data are suggesting that leisure activities should be considered to determine the appropriate TKA design. This study will provide useful data for future design and wear testing scenarios.

R.S. Ahluwalia S. Matthews R.N. Slater

We present an evaluation of basic surgical orthopaedic operative training in the last 15 years, using multiple trauma and elective training procedures in orthopaedics. Identifying the influence of competency training and EWTD on Basic Surgical Training. Whilst trying to identify the area’s the MMC should concentrate on to provide a competent trainng programme.

We assessed clinical exposure using 45 Basic Surgical Trainee Logbooks, from posts in 1990 (n=6), 1995 (n=7), 2000 (n=10), and 2004–5 (n=22); and looked at numbers of carpel tunnel decompression, and emergency hip, wrist, and ankle surgeries conducted. As well as the number of external fixators trainees were exposed to. In the 2004–5 group we prospectively assessed competency and knowledge of fracture neck of femur surgery.

From a peak in operative surgery in 1990 numbers have fallen. Today, BST’s participate in 165 emergency hip cases (mean 4.6 procedures per trainee), today, 4.8% (n=8) as primary surgeon. In 1990, and 2000 trainees were primary surgeon in 43.4% (n = 12/32) and 25.2% (n=33/131) respectively.

Trainees are comfortable with closure of skin, subcutaneous and muscular layers but not access; 91% (n=20) required assistance in positioning, and reduction, and recognition of correct alignment. Only 9.1% (n=2) felt competent without senior supervision (mean Orthopaedic BST experience 15.3 months) in hip surgery; whilst none knew of an intra-operative technique to reduce young adult capsular hip fractures. With regards to wrist and ankle fixation the decline has been dramatic decline by 11.1 and 5.9 procedures per trainee. Whilst, the numbers of forearm manipulations peaked in 1990–1995; it has since dropped to less than 5 per trainee in 2005 from 15–16. In 2005, it was also seen that a in a 6 month period a trainee in a typical district general hospital would be lucky to see an external fixator applied (average 0.6 per trainee in 6 month period).

The decline of elective surgery is shown in carpel tunnel decompressions attended. In 1990 9.8 (6–14) were conducted as a primary operator, in 2005, it was 0.5 (0–3). The greatest decline in procedures of 46.3% occurred between 2000, to 2005. A comparison of total operating showed 88.9 (n=79–125) procedures in 6 months were lost between 1990 and 2005; with a 58.6% loss in trauma.

This study suggests deficiency in operative competence today due to reduced opportunities. Thus emphasis should be placed on rota’s being matched to operative exposure, as trainee case numbers have declined sharply particularly in the last 5 years. The MMC should therefore ensure that trainees in the ST1 to 3 years reach their competencies with adequate time in the operating theatre.

Full Access
A. Khurana H. Tanaka

Introduction: Trauma surgery creates enormous mental stress for operating surgeons, especially in trainees. This is responsible for sympathetic hyperactivity which can be measured by various cardio vascular variables. Air Traffic control is recognised as one of the most stressful occupations with accepted risks and incorporated remedies. We compared the stress during surgery with that experienced by air traffic controllers.

Materials & Methods: The study included 40 trainee doctors. We obtained multiple readings of heart rate, diastolic and systolic Blood Pressure with ambulatory monitoring methods when they operated. This was compared to their resting measurements obtained at home. Similar measurements were performed for Air Traffic controllers, while at work and at home.

Results: The heart rate and blood pressure were increased at the beginning and during surgery. Student t test was applied to compare the mean values obtained intra-operatively and in resting conditions. This suggested the increase to be statistically significant. This increase in autonomic function variables was compared with the values similarly obtained for Air Traffic Controllers. Operating surgeons manifested significant increase in comparison to the other group.

Discussion: Stress can not be eliminated but can be over come with experience. Recurrent sympathetic hyperactivity may contribute to various stress related ailments. As in Air Traffic controllers, stress should be accepted as integral part of occupation. Stress relieving manoeuvres should form an important part of surgeons’ occupational health and medical school/ foundation years curriculum.

Conclusions: Surgeons experience more emotional and mental stress than occupations accepted to be most stressful.

E. Betti M. Vitale M. Vaglini

The choice of the treatment of tibial plateau fractures remains a controversial topic in current traumatology practice. The best treatment must have three fundamental requirements: to be less invasive as possible, to result in a good reduction, to have a good stability.

Surgical approach with percutaneous indirect articular reduction by elevating,minimal osteosynthesis and the use of NORIAN Skeletal Repair System lets us reach three fundamental objectives stated before.

NORIAN S.R.S, used to fill the bone gap resulting from the traumatic collapse of the metaphyseal bone, with its mechanical strength allows the stabilization of the joint fragments, the reduction and the relative ostheosyntesis, thus greatly shortening the functional recovery time.

We reviewed 70 patients affected by tibial plateau fractures, treated with this percutaneous technique using the mineral bone substitute Norian:

56 fractures were unicondylar, 21 type 41-B2 and 35 type 41-B3 (according to AO/OTA classificaction); 14 fractures were bicondylar (AO/OTA 41-C3).

The minimum follow-up was 1 year. We used for clinical evaluation the Hohl assessment form, for the radiographs the criteria of Rasmussen. X-rays. The final conclusions, resulting from integrated analysis of the clinical data and X-ray data, can be simplified and represented as follows: 52 cases could be considered excellent-good (74%), 14 fair (20%), and 4 poor (6%).

We can claim that the recostruction of the tibial plateau by minimal invasive surgery such as the percutaneous indirect reduction by elevating minimal osteosyintesis and mechanical stability assured by NORIAN SRS, is a good improvement in order to cutdown the functional recovery time. Mobilization is allowed the day after surgery and weight-bearing within the first week in B2 e B3 fracture type and within four weeks in C3 type reducing to the minimum knee posthraumatic stiffness.

D. Katsenis A. Kouris N. Schoinochoritis N. Savas K. Pogiatzis

Purpose: To assess the function of the knee joint and the development of knee arthrosis, at seven years postoperatively, in patients in whom a high energy tibial plateau fracture had been treated with minimal internal fixation augmented by small wire external fixation frames.

Material and Methods: Between October 1989 and November 1999, one hundred twenty nine high energy tibial plateau fractures were treated with hybrid fixation including small wire circular or hybrid frames, minimum internal fixation and occasionally provisional extension of the external fixation to the distal femur. The average patient age was 39 years. There were 69 (53%) C1 fractures, 19 (15%) C2 and 41 (32%) C3 fractures and 49 (38%) fractures were open. Complex injury according to Tscherne-Lobenhoffer classification was recorded in 87 (67%) patients. Clinical, subjective, objective and radiographic results were evaluated after an average follow up of 84 months.

Results: Results were assessed according to the criteria of Honkonen–Jarvinen. Excellent or good functional result was recorded in 98 (76%) patients. However, only 74 (57.5%) patients retained an excellent or good radiographic result at the final follow up. Compared with the radiographic appearance of the post-traumatic arthritis after an average of 48 months, there was found no statistically significant deterioration of the knee arthrosis (p< 0,05). No reconstruction operations were performed after the completion of the index procedure.

Conclusion: A high percentage of radiographic post-traumatic arthritis should be expected, after high energy tibial plateau fractures had been treated with minimal internal fixation augmented by small wire external fixation frames. However, because all the objectives of the fracture treatment can be obtained, the functional results remain satisfactory over time.

M. Ricci E. Vecchini A. Costa A. Sgarbossa P. Bartolozzi

PURPOSE OF THE STUDY: Arthroscopic assisted treatment of tibial plateau fractures may reduce morbidity compared to open articular surgery, but bony fixation is necessarily percutaneous and minimal. The purpose of our study was not only to assess immediate results but also long term functional and anatomic results after arthroscopic treatment of tibial plateau fractures, with special reference to radiographical Results:

MATERIAL AND METHODS: seventy patients (mean age 47 years, range 18 to 72 years, 43 men, 27 women) were arthroscopically assisted treated for a fresh tibial plateau fracture. According to Schatzker classification, there was 20 type I, 27 type II, 18 type III and 5 type IV. The fixation device was: Kirchner wire in Schatzker I, percutaneous cannulated screw in Schatzker II,III,IV, and bone cement filing of the fracture site in 1 case. In 32 cases, where bone loss was significant. we use autologous bone graft, in 18 cases SRS. There were 15 meniscal injuries: 3 underwent arthroscopic suture, 8 had partial meniscectomy and 4 sub subtotal meniscectomy. We also diagnosticated 7 lesions of the medial pivot 6 ACL, 1 PCL : all were left in place. Al patients in the first post-operatory day start passive rehabilitation with kinetech All cases were suitable for immediate post op follow up. 19 were reviewed at long term. A clinical (Hospital for Special Surgery) and radiographical examination were done with an average follow-up of 46.7 months.

RESULTS: There were no complications except two immediate compartimental syndromes that stopped the arthroscopic treatment. Passive motion of the knee started at 1 day postop with no pain. Mean flexion at 3 months was 130 degrees. At revision, the average score was: 93 for Schatker I, 91 for Schatker II, 87 for Schatker III, 86 for Schatker IV. In eight cases we found early signs of osteoarthritis. There were no secondary bony depression or significant valgus deformity on X-rays.

CONCLUSION: Arthroscopic management of tibial plateau fractures allows a complete articular screening. Rapid rehabilitation, short hospital stay, and low rate of complications reduce morbidity. The long term results are as good as those with open surgical technique for the types of fracture that we have treated (type III and IV). A minimal, percutaneous osteosynthesis which was the only possibility under arthroscopic control, did not modify the anatomical Results:

R. Bansal N. Bouwman S.J. Hardy

BACKGROUND: One of the prime concerns when managing patients in plaster casts is loss of reduction. There have been studies showing that proper moulding of plaster cast is critical in maintaining reduction. Recent studies have negated concerns that fibreglass (FG) casts do not allow swelling, when compared to plaster of Paris (POP) casts. However, their potential in maintenance of reduction has not been investigated.

MATERIALS AND METHODS: We compared the three-point bending properties of FG casts with POP casts over the first 48 hours. The effect of splitting the casts, at one hour and 24 hours, was studied. Also, the tolerance to handling was assessed by moving the hinge joint while the casts were setting.

Three identical jigs with hinged metal rods were designed to simulate Colle’s fracture. The bending force was provided by 0.5 kg weight applied at one end of the jig. The resultant displacement was measured to nearest 0.01 mm over the next 48 hours. Each test was repeated 6 times (total 8 groups and 42 tests).

RESULTS: Most deformation occurred within 1 hour for FG casts and 24 hours for POP casts. The total deformation in FG cast (mean 3.4 mm) was significantly less than in POP casts (mean 6.2 mm) (p > 0.05).

Splitting at 1 hour increased the final deformation of the POP cast and not of the FG cast (p > 0.05). No significant difference was noticed if the casts were split at 24 hours.

CONCLUSION: Three-point moulding with FG casts can provide better constant loading at the fracture site than the POP casts. Early setting of FG cast allows earlier splitting. We recommend clinical trials to ascertain the safety and efficacy of split FG casts.

D. Rouleau B. Benoit Y.G. Laflamme L. Yahia

Purpose: Restoration and maintenance of the plateau surface are the key points in the treatment of tibial plateau fractures. Any deformity of the articular surface jeopardizes the future of the knee by causing osteoarthritis and axis deviation. The purpose of this study is to evaluate the effect of trabecular metal (porous tantalum metal) on stability and strength of fracture repair in the central depression tibial plateau fracture.

Method: Six matched pairs of fresh frozen human cadaveric tibias were fractured and randomly assigned to be treated with either the standard of treatment (impacted cancellous bone graft stabilized by two 4.5mm screws under the comminuted articular surface) or the experimental method (the same screws supporting a 2 cm diameter Trabecular Metal (TM) disc placed under the comminuted articular surface). Each tibia was tested on a MTS machine simulating immediate postoperative load transmission with 500 Newton for 10000 cycles and then loaded to failure to determine the ultimate strength of the construct. Results: The trabecular metal construct showed 40% less caudad displacement of the articular surface (1, 32 ±0.1 mm vs. 0, 80 ±0.1 mm) in cyclic loading (p< 0.05). Its mechanical failure occurred at a mean of 3275 N compared to 2650 N for the standard of care construct (p< 0, 05).

Conclusion: The current study shows the biomechanical superiority of the trabecular metal construct compared to the current standard of treatment with regards to both its resistance to caudad displacement of the articular surface in cyclic loading and its strength at load to failure.

P. Lakshmanan A. Sharma J.P. Peehal H. David

Introduction: Avulsion fractures of the anterior tibial spine are not so common. The best form of treatment for displaced fractures is still debatable.

Aims: We aimed to analyze the results of different forms of internal fixation for avulsion fractures of the anterior tibial spine.

Material and Methods: Twenty-five patients with avulsion fractures of the anterior tibial spine had open reduction and internal fixation with different implants (AO screw, Herbert screw, stainless steel wire loop and absorbable stitch) and techniques. The mean follow up period was 3.66 years. They were evaluated clinically and radiologically, using KT 1000 arthrometer for ACL laxity and goniometer for range of movements. The outcome was measured using Lysholm Knee Score.

Results: Significant residual anterior laxity despite adequate fracture union was a common finding. Maximum ACL laxity was seen in adults in whom absorbable stitches had been used and they had a corresponding lower Lysholm score. Significant migration of the Herbert screws was noted in two of five patients in which it was used. Five of the eight patients with higher Lysholm score had AO screw fixation. Three patients with steel wire loop for stabilization of the fracture also had better results comparatively. Three individuals who had their knee immobilised in 25°–50° of flexion developed fixed flexion deformities, which took 12–18 months to recover.

Conclusions: The use of absorbable stitches as the primary method of fixation for avulsion fractures of the tibial spine should be avoided in adults. Herbert screw in this situation has a tendency to migrate. AO screws and non-absorbable loop yields better functional outcome. Immobilization of the knee in excessive flexion leads to prolonged fixed flexion deformity. Early range of movements can be achieved by replacing cast with a brace allowing flexion up to 90 degrees.

G. Erturan S.D. Deo R.A. Brooks

BACKGROUND: Complex tibial peri-articular fractures are known to be challenging with high complication rates. Techniques are evolving to assist the management of these injuries and this study looks at a Trauma unit’s experience to help evaluate indications, short and mid-term outcomes and complications.

METHOD: 4 year retrospective analysis of prospectively enrolled patients diagnosed with complex peri-articular fractures. Definitive treatment with Less Invasive Stabilisation System (LISS), low contact peri-articular plates and locking condylar plates, using minimally invasive percutaneous osteosynthesis (MIPO), irrespective of initial operative management were included. Follow up:until discharge from clinic with union and full weight bearing. Outcome: peri- and post-operative complications, loss of fixation, radiographic union, and range of motion.

RESULTS: 25 (15 proximal,10 distal tibial) operations by senior authors (RAB, SDD) over 4 years with a 16–88 year age (mean 44). Poly-trauma:7 (28%) of cases and 6 (24%) of the entire group were open fractures. Ten patients (40%): preceding damage-limitation procedure prior to definitive treatment (MIPO) and found to be over twice as likely to experience a complication compared to patients who did not. 3 (12%) of 10 had failed those alternative modalities. Overall infection rate was 24% (6 patients:2 deep wound infections; 4 open fracture wound infections). Infection was successfully managed with the use of debridement, flaps and antibiotics in 2 patients (8%); antibiotics alone on one (4%); in 3 patients with the delayed plate removal (12%), usually after union (1 revised with an intramedullary nail). Six plates (24%) were removed: 3 (12%) for infection; 2 (8%) for pain; 1 (4%) for plate fracture (revised). Other complications:2 (8%) significant wound breakdowns, one of whom required local flap cover. No mal-alignment issues; 1 patient developed common peroneal nerve neuropraxia. Patients who were operated after a week or more from injury were half (33%) as likely to suffer from a complication than those operated within a week (57%); P < 0.05 Chi-Square.

All progressed to union with 5 patients (20%) having metal work out at that end point and 8 (32%) healing without complication, further surgery or irritation. There were 18 re-operations in total in 9 (36%) of the patients.

CONCLUSION: Complex peri-articular fractures of the tibia continue to have a high re-operation rate with significant infection risk especially in open injury. Such techniques do provide a lower morbidity and short-term complication profile when compared with frames/hybrids and formal open fixation. The timing of minimal approach surgery is crucial and has yet to be fully defined. Within a department this type of fixation should be restricted to those with a specific interest, experience and training.

S. Rajkumar K. Nagarajah M. Moiz

OBJECTIVES: To review the short-term functional results of the surgical treatment of tibial plateau fractures using low profile peri-articular plates.

METHODS: Forty-nine displaced fractures of the tibial plateau in forty-nine patients were treated with open reduction and buttress plate fixation using low profile plate between 2002–2006. All aspects of their care, including tibial plateau fracture type, operative management and associated injuries, were documented. Preoperative and postoperative follow-up radiographs were analyzed for fracture classification and adequacy of reduction. All patients were followed up with clinical assessment and given Iowa knee functional outcome questionnaires. Data were also collected regarding return to work and sporting activities. The average age of the patients was thirty-eight years and the mean follow-up was 25 months, with a range of 12 to 52 months.. Of the forty-nine fractures studied, twenty-six were classified as Schatzker types I, II, or III, and the remaining twenty-three were types IV, V, or VI. Forty-six patients had closed injury while three had open fractures.

RESULTS: 48 of the fractures healed without additional surgical intervention or bone grafting except for one bicondylar fracture which needed amputation because of deep infection and soft tissue problem. Thirty eight patients had follow-up of greater than 1 year. The average time to radiographic callus was 6.2 weeks, and the average time to complete union was 16 weeks. The articular step-off average was 0.8 mm, with a range of 0 to 5 mm. The range of motion of the knee averaged 3° of extension to 120° flexion, which was an average of 87% of the total arc of the contralateral knee. The average Iowa Knee Score was 88 points (range, 72 to 100 points). The postoperative alignment demonstrated 1 patient with a malalignment of 4 degrees procurvatum and 1 patient with 3 degrees of valgus. There were two superficial wound infections and one case of deep infection.

CONCLUSIONS: Open reduction and internal fixation is a satisfactory technique for the treatment of displaced fractures of the tibial plateau, particularly for patients younger than fifty years. The use of low profile tibial plates appears to stabilize complex fractures of the tibial plateau with a low incidence of complications. The low profile plate functioned well in maintaining alignment and obtaining union in these high-energy fractures.

C. Kayali H. Agus A. Turgut

Objectives: The comminuted supracondylar femur fractures are resulted from high energy trauma. Infection and union problems are common complications. LISS is a new generation implant leading to decrease these complications. The aim of this prospective study is to compare the outcomes of distal femoral fractures treated by LISS (Less Invasive Stabilization System) of the multiple injured and isolated fractured cases.

Patients and Methods: This prospective study comprised of twentysix patients, sixteen men and ten women, who had 27 distal femoral fractures. Patients were divided as having multiple injury (group I) or isolated femur distal fractures (group II). There were fourteen supracondylar (AO type A) and thirteen intercondylar (AO type C) fractures. The average Injury Severity Scores (ISS) of group I and II were 26.7 and 9 respectively. Operations were performed according to biological fixation principles by means of submuscular manner. No grafting was performed to enhance the healing. The cases were evaluated based on the criteria of Schatzker–Lambert and modified Hospital for Special Surgery (HSS) scoring system.

Results: The mean hospitalization time was 16 days (range 13–46) in GI mainly depended on the presence of concomitant injuries and 8 days (range 6–12) in GII. The mean age of the patients was 49 years (range 26–80) (51.6 in GI and 45.6 in GII). The mean follow up period was 25.8 months. Union was achieved in all cases. Two cases required debridement procedures due to deep infection in group I. One of them healed completely but the other not resulted in chronic ostemyelitis. Revision surgery was carried out in one case due to screw pull out at second weeks postoperatively.

The average range of knee motion of the group I and II at the last control were 112.8°, 121.8 respectively. The mean modified HSSs were 73.9 and 79.9 respectively. There was no significant difference for HSS scores and range of knee motion (p> 0.05). Based on the criteria described by Schatzker and Lambert, the outcomes were assessed as excellent in 3 cases, good in 8, fair in 3, and poor in 2 in GI and as excellent in 3, good in 7 and fair in 1 in GII. Poor results of GI were because of osteomyelitis in one case and 15° varus deformity in another. The full weight bearing time was longer in group II depending on the concomitant injuries.

Conclusion: We concluded that LISS is effective method to yield satisfactory results for comminuted supracondylar fractures with multi trauma, even if their final results seem to be lower in comparison to isolated femur fractures.

A. Carfagni F. d’imperio M. rendine M. razzano

Proximal tibial fractures often are caused from trauma with high energy forces with associated soft tissue lesions. The authors report their experience with 45 cases of proximal tibial fractures treated with less invasive system plates (LISS) with good clinical and radiographic results after 5 years follow-up. There is evidence of good stabilisation of the fractures with this conservative soft tissue method combined with early rehabilitation.

M.T. Hirschmann T. Rychen L.G. Lorez N.F. Friederich

Background: Traumatic dislocations of the knee are uncommon (< 1% of all dislocations), but they account to the most serious ligament and soft tissue injuries of the knee. Diagnosis and treatment of the dislocated knee present a major challenge to the orthopaedic surgeon. The purpose of our retrospective study was to critically analyze the clinical outcome of all traumatic knee dislocations treated operatively between 1996 and 2006 in our institution.

Methods: Retrospective clinical case series study of all patients treated for traumatic knee dislocation (m: w=12:4; mean age 31 yrs, range 17–63 yrs) from 1998–2006.

The mechanism of injury was a traffic accident (n=7), a sport trauma (n=8) and slip and fall (n=1). The charts of all patients were analyzed.

The clinical outcome was assessed by personal telephone interview by a modified SSK questionnaire by Insall. Surgery was performed by one team of surgeons 2–89 days after trauma.

Mean and range were reported for continuous variables and relative and absolute frequencies vor categorial variables. Data were analyzed using Stata version 8. The level of significance was defined as p< 0.05.

Results: The injury pattern is reported below:

15 anterior cruciate ligament (ACL) lesions (11x ACL reconstruction), 15 posterior cruciate ligament (PCL) lesions (9x refixation, 3x reconstruction), 13 medial collateral ligament (MCL) lesions (8x reconstruction), 6 medial posterior collateral ligament (MPCL) lesions (4x reconstruction), 4 lateral collateral ligament (LCL) lesions (1x reconstruction), 3 popliteal muscle injuries (2x reconstruction), 5 medial meniscal lesions, 10 lateral meniscal lesions (9x suture, 1x partial meniscectomy), 3 femoral fractures, 1 proximal tibial fracture.

One angiography was performed. No vascular lesion was observed.

The follow up rate was 93% complete. The mean follow up time was 58 months (range 35–156).

83% of patients were able to return to work without any impairment. 62% of patients returned to the same level of sport activity. 54% of patients were absolutely painfree.

Based on a modified SSK score by Insall a mean of 182 points (range 129–200) on a scale with maximum 200 points could be noted.

Conclusions: Even though in a orthopaedic clinic specialized in the treatment of knee injuries traumatic knee dislocations remain a demanding therapeutic challenge. A highly specialized, customized and sophisticated treatment strategy of a experienced team of surgeons, nurses and physiotherapists is mandatory for acheivement of optimal functional and subjective outcome.

S. Ahmad H. Jahraja D. Sunderamoorthy K. Barnes L. Sanz M. Waseem

We are presenting a prospective study of 25 patients with clavicle fracture treated with Rockwood Intramedullary pin fixation. Operative management is required for open fractures, neurovascular injury or compromise, displaced fractures with impending skin compromise and displaced middle third fractures with 20mm or more shortening. Plate osteosynthesis or intramedullary fixation devices are used for operative management.

Patients and Methods: 25 patients with clavicle fractures underwent fixation of clavicle fractures with threaded intramedullary Rockwood pin. The indications for internal fixation were persistent wide separation of fracture with interposition of soft tissue in 12, symptomatic non-union in 3, associated multiple injuries in 3,one of them had a floating shoulder, impending open fracture with tented skin in 4 and associated acromioclavicular joint injury in 3 and one of whom had bilateral fracture clavicle.. All patients underwent open reduction through an incision centred over the fracture site along the Langer line. Intramedullary pin was inserted in a retrograde manner. Autologous bone grafting from iliac crest was done in all patients with nonunion. Radiographic and functional assessment conducted using DASH scores.

Results: There were 21 male and 4 female patients with a mean age of 34 yrs (range 17 to 64 yrs). Mean follow up was 12 months (range 5 months to 30 months). Radiographic union occurred in all patients within 4 months. In our study the commonest indication for Rockwood pin fixation was displaced middle third clavicle fracture followed by impending open fractures. Commonest complication was skin irritation at the distal end of the pin with formation of a tender bursa occurring in 9 patients, 3 of whom had skin breakdown. Fracture union occurred in all these patients with no further intervention and wounds healed completely after removal of the pin. One patient developed non-union and was later treated with ORIF with DCP and bone-graft. There were no deep infections, pin breakage or migration or re-fractures after pin removal. At the time of last follow up the average DASH score was 25 with a range of 18 to 52.

Conclusion: Open reduction and intramedullary fixation of clavicle fractures with Rockwood pin is a safe and effective method of treatment when surgical fixation of displaced or non-union of middle third clavicle fracture is indicated. This technique has an advantage of minimal soft tissue dissection, compression at the fracture site, less risk of migration and ease of removal, along with early return to daily and sports activities.

R. Attal M. Müller M. Hansen H. Bail M. Kirjavainen T. Hammer M. Blauth D. Höntzsch P. Rommens

Introduction: The Expert Tibia Nail was designed to address proximal, shaft, segmental and distal tibia fractures in one implant. Multiple locking options in various directions provide more stability and reduce the risk of secondary malalignment. Angle stable cancellous bone locking screws in the tibia head also improve fixation.

We evaluated this new implant in our series in a prospective, multicenter setting.

Methods: 190 patients were treated in 10 participating centers using the Expert Tibia Nail (Synthes). 127 patients suffered polytrauma, 58 presented as open fractures. Within the framework of the study 5 cases were proximal tibia fractures, 108 shaft fractures, 56 distal fractures, and 21 segmental fractures. These were followed-up postoperatively, after 3 months and one year and evaluated radiologically and clinically with regard to malalignment, union rate and complications.

Results: Non union occurred in 9 cases after one year of follow up (n=150). 20 patients showed delayed union. The rate of open and complex fractures was high in this group. Dynamisation was performed in 10 cases. Valgus/varus and recurvatum/antecurvatum malalignment of more than 5 degrees occurred in 13 cases. Stable reduction was achieved in 144 cases. In 4 complex fractures, initial reduction went into malalignment. 2 patients developed a deep infection after 3rd degree open fractures. 34 patients suffered from pain in the operated area. 6 screws broke during the follow-up.

Discussion: The Expert Tibia Nail proved to be an excellent tool to treat tibia fractures. Not only shaft fractures but also complex fractures in the proximal and distal metaphyseal area can be successfully stabilized due to advanced locking options and design of the nail. The rate of malalignment, non-union and complications was low.

A. Athanasopoulou V. Psychoyios G. Galani H. Dinopoulos M. Domazou A. Tsamatropoulos

Aim: The aim of this study is to evaluate the efficacy of the multidetector CT scan in shoulder fractures and to correlate these findings with those of plain x-rays.

Material and Method: A 105 patients with shoulder fracture were examined with a multidetector CT scanner after the acute injury. There were 64 male and 41 female with an average age of 52 yrs (range 16–95 yrs). The examination was performed with a CT PHILIPS BRILLIANCE, and six groups of detectors were used, with thin slices (1.6–2 mm). MPR and three dimensional reconstructions were performed.

Results: The mechanism of injury was fall during walk in 66 patients, fall from a height in 11 patients, and road traffic accident in 28 patients. They were detected 210 fractures at the shoulder region. A 135 fractures were located at the proxd imal end of the humerus, 75 at the scapula, in 95 out of 105 patients. In 10 patients with a comminuted fracture of the upper end of the humerus, the exact number of fragments as well as the precise location of them was not accurately assessed with plain xrays. MDCT control with multilevel anasynthesis and three dimensional reconstruction improved the understanding of the anatomic orientation in complex fractures and fractures–dislocations and in detection of subluxation of the fragments of the shoulder headin four part fractures in two patients.

Conclusion: Our results would orient us for using the MDCT scan in patients with acute shoulder injury, especially in cases with comminuted fractures, because it is better assessed the place, the orientation and the displacement of fragments, which are not easily identified in plain xrays. Furthermore, these reconstructions improve the preoperative planning in those patients

Full Access
B. Speigner T. Gosens

Background: Body fractures of the scapula are generally treated nonoperatively, and few functional deficits have been reported. Whereas prior investigators have presented radiographic and surgeon-based outcomes, we used a patient-based outcome questionnaires and objective range of motion and muscle-strength testing to evaluate a series of patients who had received nonoperative care for a fracture of the body of the scapula.

Methods: We identified twenty-three patients (seventeen men and four women with a mean age of forty-four yours) who had sustained an isolated fracture of the body of the scapula. All patients were treated non-operatively. At a mean of sixty months, and a minimum of thirty months, outcomes were measured with the Constant shoulder score, the DASH (Disabilities of the Arm, Shoulder and Hand) and the RAND 36 (Rand 36 item Health Survey) patient questionnaires. Additionally we …

Results: On all scores a good to excellent result was obtained in those patients with an isolated scapular fracture. In those cases in which the scapular fracture was a part of a multi-trauma, the amount of accompanying injuries correlated with the inferior result.

Conclusions: Overall outcome of scapular fractures is good but the final result is dictated by the severity of accompanying injuries.

J. Vastmans T. Poetzel S. Hauck V. Buehren

Due to the fact that the treatment of distal femoral fractures is a therapeutic challenge, new specific implants were continuously developed. The techniques should guarantee a reliable bone healing for two different groups. For young patients with high energy trauma and more or less severe collateral injury and for old patients with osteopenic bone, weal soft tissue and a high rate of co-morbidity. Present widespread techniques are reduction and fixation with LISS plate or retrograde nails. In this clinical study from 2003 to 2006 we compared our supracondylar nail (SCN, Stryker) with the LISS plate. We were looking at a series of 77 patients (55 SCN and 23 LISS) with A (36) and C (41) fractures of the distal femur. 43 (78%) of the SCN group healed without complications, 1 malrotation, 1 case of infection, 2 pseudarthrosis and 5 problems with the distal locking screws were observed. In the LISS group only 23 (56%) healed primarily, whereas the complications occured more frequent. Beside radiographic control and clinical examination the success of operation was assessed with a standardised questionare (KOOS). The SCN group showed again a higher rate of satisfaction compared to LISS.

Conclusion: The SCN is working in A and also in complex C fractures. Furthermore we saw less rate of complications and more satisfied patients with the SCN.

R. Chidambaram C. Kachramanoglou D. Mok

Aim: To evaluate the radiographs of proximal humeral fractures in an attempt to define a diagnostic sign as a predictor of four-part fracture.

Diagnostic sign: The normal humeral head articular surface points towards the glenoid. We describe our ‘sunset’ sign as ‘articular surface of humeral head pointing away from the glenoid and tilted upwards, in the presence of a displaced greater tuberosity fracture’. We postulate that a patient with proximal humerus fracture showing this sign has four-part fracture until proved otherwise.

Materials and Methods: Between 2002 and 2006, 80 consecutive patients underwent open reduction and internal fixation of their proximal humeral fractures in our Shoulder unit. We reviewed their preoperative radiographs and operative notes retrospectively. 79 patients were included in the study as one patient’s pre-operative radiograph was not available.

The AP radiograph was evaluated independently by three observers who were blinded to the identity of the patients and their operative diagnosis. The presence of ‘sunset’ sign was recorded. There was 90% inter-observer agreement. In the remaining 10%, a consensus review was performed as to the presence of sign for evaluation purpose. The findings were then correlated with the operative findings to confirm whether they were four-part fractures or not. With 95% confidence interval we calculated the sensitivity, specificity, and positive and negative predictive values for our diagnostic sign.

Results: 30 out of 79 patients displayed ‘sunset’sign in their preoperative radiograph. Of these 28 had confirmed four-part fractures operatively. The positive predictive value of ‘sunset’ sign in diagnosis the four-part fracture was 93%. The specificity and sensitivity were 95% and 78% respectively. The sensitivity was affected by 8 patients with four part fractures with displaced articular head fragment which had dropped either medially or posteriorly.

Conclusion: Our results suggest that in patients with proximal humeral fractures, the presence of ‘sunset’sign in the anteroposterior radiograph is a reliable indicator of four-part fracture.

T. De Baere T. Lequint

We present the results of surgical treatment of proximal humeral fractures in a group of 40 patients. The fractures were treated with the angular stable Lockin Proximal Humeral Plate, which is based on the LCP-principle (Locking Compression Plate). The upper part of the plate contains small suture holes for fixation of the tuberosities.

Between january 2002 and december 2005, 40 patients were operated using this technique. There were 24 women and 16 men and the mean age of our population was 56.5 years. Clinical and radiological evolution was followed until fracture fracture healing and functional recovery and a Constant-score was taken on a retrospective basis with a mean follow-up of 23.6 months. During follow-up 2 patients died of unrelated causes with their fractures healed and 2 patients were lost because they were living abroad.

Fracture healing was uncomplicated in 34 patients (89 %). In 4 patients there was secondary displacement of the fracture: varus displacement in 3 cases and complete loosening of the osteosynthesis in a patient who fell again a few weeks after the first intervention. In this patient a new osteosynthesis with the same device was realised and the fracture healed correctly. In the other 3 cases the fracture healed with some varus alignment and in 1 of these the hardware had to be removed because of intra-articular positioning of some screws after varisation of the humeral head. No secondary displacement of the tuberosities was seen. In one case we had an aseptic necrosis of the humeral head 6 months after the osteosynthesis and this patient needed a shoulder arthroplasty. Another patient had severe chondral lesions of the humeral head but symptoms respond well to medical treatment.

Hardware removal was necessary in 8 patients because of subacromial impingement or local tenderness. Reflex sympathetic dystrophy occured in 4 cases. The mean Constant-score was 57.6; when correction was made for age and gender the mean score was 73.0.

Conclusion: The LPHP plate is a reliable implant for proximal humeral fractures but attention should be paid to the possibility of subacromial impingment and the plate should not be placed too high. Although the LCP-system allows for rigid fixation, some loosening of the humeral head screws in osteoporotic bone remains possible, leading to varus displacement of the humeral head. In these cases early mobilisation should be avoided. Secure fixation of the tuberosities through the proximal suture holes is also mandatory if early mobilisation is foreseen.

We report the short-term results of an alternative treatment for acromioclavicular (AC) dislocation.

36 patients, aged 20 to 58 (mean 36), with Tossy types IV (16) or V (20) AC-injuries were operated on within 1 week after trauma. The majority of patients had sport-related injuries. All patients were engaged in overhead activities, either professionally or for sports. The surgical technique consisted of a double fixation. A processed tendon-graft, either fascia lata or tibialis anterior, was looped around the coracoid process and the distal clavicle in a figure-of-eight and sutured onto itself after reduction of the dislocation. The AC discus was removed if damaged. No attempt at repair of the ligaments was made. The graft was protected for 6 weeks with 2 percutaneously placed acromioclavicular K-wires. In this period pendulum exercises and up to 45° abduction were allowed.

21 patients had an excellent result with painfree function, including full range of motion and strength, at only 3 month postop; another 5 needed 6 months to reach an excellent result. These patients could fully return to their work or sports activities at 3 months postop. 5 developed frozen shoulder syndrome and had a poor result at 3 month postop. These patients recovered well and all had good or excellent results at 8 month postop. 3 patients refused follow up after removal of their K-wires and 2 refused follow up beyond 3 months, at which time their result was good (1/5) or fair (4/5).

Although a good to perfect reduction was obtained perop, X-rays showed perfectly maintained reduction in only 12 shoulders. 15 patients had minimal loss of reduction (< 5mm), 7 had < 100% ascension of the clavicle and 2 had > 100% ascension.

Complications were rare, with 3 patients having early pin migration or removal due to infection which led to loss of reduction. 3 other patients had minor AC wound problems and another 2 pintract infection; all without further consequences.

The use of a processed tendon-graft to reconstruct the coracoclavicular ligaments, protected by 6 weeks of K-wires, appears to be a valuable treatment option for Tossy grades IV and V AC injuries. This technique allows rapid recuperation of full function as well as return to work and sports in the majority of patients.

R. russo M. Ciccarelli L. Vernaglia Lombardi G. Giudice M. Gallo F. Cautiero

Aim: To describe a new surgical technique for the reconstruction of complex fractures of the proximal humerus that can be used in both young and elderly patients. It consists in the anatomical reconstruction of fragments as puzzle with used of bone block and small fragment bone between the methaepiphiseal and head before a minimal osteosinthesis with K.-wire and or cannulated screws and or surure bone.

The goal of this technique is to restore normal anatomy of proximal humerus around a bone bridge inside the head and the metaphysis.

Methods: From 2003 to 2005 we treated 25 patients (17 males and 8 females), average 49.6, with a 3- or 4-part fractures and fracture\dislocations. The surgical technique requires a medial reconstruction with bone block insert and osteosyntesis with minimal encumbrance(k-wire and cannulated srews). In eleven cases we used autologus platelet growth factor

Results: All cases were submitted X-ray at 3months 6 months and 1 years. ten cases, also had TC scan. The functional results were evaluated according to the Constant score. With a mean follow-up of 24 months (range from 12 to 36 months), the results were excellent or good in 24 patients; the mean active forward elevation was 160 degrees. In one case we found a sintomatic avascular necrosis that was resolved with a hemiarthroplasty.

Discussion: Surgical management of acute complex proximal fracture of the humerus is still a challenge to the surgeons, both in young and in elderly patients.

The Authors report the goal of this technique is to restore normal anatomy of proximal humerus around a triangle-shaped bone block positioned inside between the head and the metaphyseal. The fragments are then stabilized with a minimal osteosynthesis by K- wires, screws or bone sutures.

The results of our study show that the technique we propose has good clinical and functional outcomes, with a low percentage of complications.

G. Roederer F. Gebhard L. Kinzl

Purpose: Early results of MI treatment of proximal humeral fractures in mainly osteoporotic bone stock using the NCB®-PH plate showed promising results reaching 62 points (86% of age related normal value) in Constant Score 6 months postoperatively (Roederer et al., submitted, 2006). The purpose of this study was to analyze the long-term results focusing on functional outcome and complications.

Methods: So far out of a total number of 90 cases we have gained the data of 35 patients (24 women, 11 men; age 68 in the mean) who sustained fractures of the proximal humerus treated MI with the NCB-PH® plate (Zimmer Company, Winterthur, Switzerland). In 16 cases (46%) osteoporosis has been diagnosed pre-operatively. Radiological follow-up in two planes and functional outcome is assessed clinically (ROM) and using visual analogue scale (VAS) for pain and function, Constant Score and a modified adl score (activities of daily living).

Results: Average ROM (in degree) for anteversion was 101, glenohumeral abduction 87, external rotation 31 and internal rotation 81. Average VAS for pain was 1, 9 points (10 = worst) and for function 6, 4 points (10 = best). Average Constant Score was 65 points, average adl score was 16 points (30 = best). Between 6 and 12 months postoperatively one case (2, 9%) of sintering of the humeral head and one case (2, 9%) of avascular necrosis was detected. In 3 cases (9%) of reversed impingement we performed total removal of hardware. Four younger patients (11%; age 60 in the average) underwent the same procedure demanding it though not suffering of limited ROM or pain.

Conclusion and Significance: In the early results NCB-PH® proved to be an effective MI method of treatment of fractures of the humeral head in the elderly patient with mainly osteoporotic bone stock. The 1 year follow up data show further functional improvement (approx. 5% of Constant Score). The complication rate remains low (5/35 = 14%).

Especially, no cases of lesions of the axillary nerve or frozen shoulder were seen. The latter we believe is due to the MI procedure and the early functional treatment due to high primary stability of the NCB-PH® plate. Despite good functional outcome, younger patients with higher levels of activity compared to the average patient sustaining proximal humeral fractures tend to feel subjective problems with the plate in situ demanding surgical removal of hardware. The long-term results also prove the NCB-PH® plate to be a safe and effective method of treatment reaching a functional outcome that enables the mostly old patients to regain an acceptable level of activity. Removal of hardware is easy to perform and offers especially in the younger patient a possibility to at least improve patients’ subjective outcome

T. Taneja D. Zaher A. Koukakis C. Apostolou S. Owen-Johnstone T. Bucknill A. Amini D. Goodier P. Achan

The aim of our study was to assess the use of the Clavicular Hook Plate in treating acromio–clavicular joint dislocations and fractures of the distal clavicle. The prospective study was carried out at two hospitals- a teaching hospital and a district general hospital.

Between 2001 and 2004 a total of 37 patients with AC joint injuries and distal clavicle fractures were treated surgically with this device. Four of the patients had sustained a Neers Type 2 fracture of the distal clavicle, while 33 patients had acromio-clavicular joint dislocation (Rockwood Type 3 or higher). Mean age of the study group was 35.2 years. Post operatively, shoulder pendulum exercises were commenced on the second day and all patients discharged within 48 hours. During the first few weeks, we restricted shoulder abduction to 90 degrees. At the first postoperative follow up appointment at 2 weeks, average shoulder abduction was 30 degrees and forward elevation −40 degrees. This improved at 6 weeks to 85 degrees and 105 degrees respectively. The plates were removed at an average time interval of 11 weeks for the ACJ dislocations (range 8–12 weeks) and 15 weeks for the clavicle fractures (range 12–16 weeks). At three months after plate removal, we evaluated patients to measure the Visual Analogue Score(VAS) and Constant Score. The mean VAS was 1.4 (range 0–6) and the mean Constant score was 92 (range 72 to 98). Wound healing problems occurred in two patients, while two had a stress riser clavicle fracture. These had to be subsequently fixed with a Dynamic Compression Plate. One patient developed a superficial wound infection. Seven patients had problems due to impingement between the hook and the under surface of the acromion. A 45 year old female patient developed ACJ instability after plate removal. Radiographs revealed widening of the AC joint and some osteophyte formation. She went on to develop frozen shoulder which was treated with intensive physiotherapy.

The AO hook plate represents an improvement over previous implants in treating injuries around the AC Joint. However, the need for a second operation to remove the plate remains a significant problem. Complications resulting from impingement were common in our patients and represent a major drawback of this implant.

F. Brunner C. Sommer C. Bahrs R. Heuwinkel C. Häfner P. Rillmann G. Kohut M. Müller R. Babst

OBJECTIVES: In recent years the incidence of proximal humerus fractures increased strongly. The optimal treatment of displaced, unstable fractures is still controversial. One of the major problem seen in previous treatment options was implant failure with secondary dislocation, pseudarthrosis and AVN. New angular stable implants promise a stronger anchorage and allow early functional aftertreatment, especially in osteopenic bone. Aim of this prospective case-series was to assess complication risks and functional outcome after ORIF with an angular stable form plate

DESIGN: Prospective case-series

SETTING: Multicenter study in 8 European Trauma Units

PATIENTS: 157 patients were treated for 158 displaced proximal humerus fractures


RESULTS: According to the AO/ASIF classification 25%, 61% and 37% were classified as type A, B and C, respectively. One year follow-up rate was 84%, whereupon 6 patients had died in the mean time and 18 were lost to follow-up. Overall 71 complications were observed in 53 patients and led to 39 unplanned re-operations, whereupon most frequent were primary screw perforations (n=22), secondary screw perforations (n=13)–mostly with secondary impaction (n=11), and AVN (n=8). Increasing age and severity of fractures influenced the occurrence of complications, since the risk to obtain a complication was doubled in patients over 60 years compared to younger (Relative Risk 1.9; Fischer’s Exact, p=0.022) as well as in AO/ASIF B- and C-fractures compared to A-fractures (Relative Risk=1.8; Fischer’s Exact, p=0.05). Risks for complications related to the implant, surgical technique or fracture and bone were 9%, 20% and 13%, respectively. Within one year all fractures healed and 5 secondary dislocations were observed. The mean (SD) Constant score of the injured shoulder improved during follow-up period to 72 points (15.2) at 12 months follow-up, when 87% (16.6%) of the contralateral shoulder was reached. Across all follow-up examinations the Constant score in relation to the contralateral shoulder impaired with increasing severity of the fracture (ANOVA, p=0.006). The mean (SD) DASH score after one year was with 16 points (21.1) worser (T-test, p< 0.001) than before the accident [5.2 (11.4)].

CONCLUSIONS: Fixation with a Philos plate provides high stability to preserve achieved reduction, which benefits the good functional outcome. However surgical technique related complication risks are high, particularly due to screw perforations into the joint. Augmented awareness and improvement of surgical technique should reduce these risks. Complex fracture types and higher age increases the risk to sustain complications, where as only severity of fractures impairs the functional outcome.

J. Blum M. Hansen M. Müller P.M. Rommens H. Matuschka A. Olmeda

Introduction: There is an increasing tendency for internal fixation of proximal metaphyseal fractures. Intra-medullary nailing only recently has been considered to be a valuable option in these cases. Through the development of new reliable implant types, nailing finds increasing acceptance.

Questions: Is intramedually nailing with a new angle stable titanium nail a safe procedure in the treatment of proximal humeral fractures and is it combined with a good outcome?

Material and methods: A prospective international mul-ticenter study with standardized study control focused on the “Proximal Humeral Nail (PHN–Synthes Inc.), possible complications and clinical outcome. 151 fractures had been treated in 11 hospitals, where 72 were A-type, 67 B-type and 12 C-type (AO). There were 37 male, 114 female patients, median age 66 years ranging from 16 to 97 years. The outcome had been measured through Constant-Morley scores and DASH scores. 108 patients could be followed up until 1 year postoperatively.

Results: Important complications were perforation of the articular surface by screw or spiral blade (n=8), pain due to the implant (n=10), dislocation of fragments (n=2), non union (n=2), humeral head necrosis (n=3) and wound infection (n=1). The Constant-Morley score shows in total mean values one year postoperatively 75.3 in the injured and 89.9 in the non-injured side. The DASH score pre-operatively was in total 5.9 and 9.3 one year postoperatively, where the best results could achieve 0 points, the worst 100 points.

Discussion: Analyzing the complications, perforation of the articular surface by screw or spiral blade and pain due to the implant or impingement at the nail base are clearly related the technical failure in performing nailing. Here or the nail has not been introduced profoundly enough or the length for the spiral blade was not determined exactly and probably not controlled intraoperatively. This is due to the individual accuracy of the surgeon. The development of non-union (2/108) shows a ratio equal or even better to what is reported in conservative treatment or plate osteosynthesis. Dislocation of fragments n the other side, show the limit of this procedure, where in multifragmentary fracture type one spiral blade will not be able to fix a fragments. Using additional hardware is possible, but might reduce the effect of an initially low invasive approach. Constant score and Dash-score results perform similar to plate osteosynthesis, where clearly C-type-fractures present the worst prognosis.

Conclusion: Proximal humeral nailing seems to be beneficial in A-type metaphyseal fractures. Even in many B-type fractures it is still a good alternative with limited incision to the plate osteosynthesis.

In C-type fractures it is not advisable as a standard routine, only for experienced surgeons it might be a possible solution in selected cases.

S.N. maripuri D. Lewis R. Evans C. Dent R. Williams

Introduction- Proximal humeral fractures remain a challenging problem. Most authors agree that anatomical reduction and stable fixation are essential to allow early range of motion. A variety of techniques have been described such as threaded pins, tension band wiring, screws, nails, plates and primary prosthesis. Locking plates score over other implants by the virtue of providing greater angular stability and better biomechanical properties. The Aim of the Study is to evaluate the functional outcome of PHILOS plate Osteosynthesis of displaced proximal humeral fractures.

Materials and Methods- A retrospective study of 50 patients treated with PHILOS plating for the 2 part, 3part and 4 part proximal humeral fractures with a minimum follow up of 1 year. All the patients were assessed in clinic by Constant Murley and ASES scoring systems. X-ray evaluation was done for fracture healing, AVN, mal-union, non-union, collapse of head, screw penetration and impingement of plate.

Results- Total of 50 acute displaced fractures of proximal humerus treated with PHILOS plating between 2003–2005 were assessed. Mean age was 64 years (15–86) Male to female ratio was 12:38, dominant to non-dominant ratio was 32:18. According to Neer’s classification 16 fractures were 2 part, 24 fractures were 3 part and 10fractures were 4 part. The overall mean Constant score was 73.4(range20–100) and ASES score was 71.7(range 25–98). Under 60 years of age the mean Constant and ASES scores were 83.5 and 83, over 60 years of age scores were 63.1 and 60.4 respectively. The complications include two deep infections which needed excision arthroplasty, one malunion, one subacromial impingement which needed plate removal after fracture healing. No mechanical failure, no non-union, no ANV was noted.

Conclusions- PHILOS plate Osteosynthesis is a reliable method of treating complex proximal humeral fractures. It provides good mechanical stability and allows rapid mobilization with out compromising fracture healing.

L. Obert P. Clappaz D. Gallinet P. Garbuio

Introduction: The three or four-part fracture of the proximal humerus remains a challenging fracture in the case of elderly patient. In this continuing prospective study we compared the outcome after implantation of a shoulder hemiprosthesis of the anatomical generation and a reversed prosthesis.

Material and methods: 34 shoulder prosthesis were implanted in patients older than 70 between june 1996 and june 2004. All patients were evaluated by a surgeon not involved in treatment concerning activities of daily living (DASH scoring), clinical outcome (Constant-Murley Score), radiological results, and a summary of complications.

Group 1: anatomical prosthesis (Tornier): At an average follow-up of 16,5 (range 6–55) months, 13/17 patients with an average age of 78,6 years (70–95), were evaluated.

Group 2: reversed prosthesis (Depuy): At an average follow-up of 12,6 (range 6–18) months, 13/17 patients with an average age of 77,1 years (70–84), were evaluated. In this group functional treatment was started immediately after surgery.

Results: concerning age, follow up and dash scoring there were no difference between two groups. In reversed group : the outcome was better (Constant-Murley: 79,5 (57,8–100) vs 57,1 (21–85) p=0.005), the average active elevation was better by 30° (p< 0.001) and the average active abduction was better by 53° (p< 0.001). 7/13 cases of glenoid notching stage 2 or 3 were noted. In anatomical group : the average active external rotation was better by 10° (p=0.01). Tubercle fixations failed in 6/13 cases.

Discussion: No comparative study has still been published between the two sort of implant in elderly patients. Our results of shoulder arthroplasty in acute injury to the proximal humerus with reversed prosthesis are in agreement with the preliminary results reported by Sirveau. At short follow up, reversed prosthesis allow to reach early mobilisation with best functional results. Rotation remains the key point : with a significant gain in active abduction and elevation the reversed prosthesis group do not reach a better dash scoring. Attachment fixation of the posterior rotator cuff must probably be discussed in reversed prosthesis in acute fracture.

R. Russo L. Vernaglia Lombardi M. Ciccarelli G. Giudice F. Cautiero

Aim: The authors report a new ostheosinthesis device(Prysmatic Threeangular System P.T.S.) designed for the treatment of complex fractures of the proximal part of the humerus.

Methods: From May 2005 to February 2006 we treated ten patients, four patients were female and six male. The average age was 45.1 years (max. 69, min. 27). Cases included nine fresh fractures and a malunion of three-part fracture treated three months after the trauma. All patients had closed fractures; one was worsened by a partial and temporary lesion of the brachial plexus. All patients underwent a standard X-ray and a Ct scan. In all patients, some homologous spongy bone was inserted in the titanium structure; moreover, in five cases (the youngest patients) autologous blood-derived growth factors were added. All patients were kept immobilized by means of a brace with internal rotation for 4 weeks.

Results: In 6 cases the follow-up period ranged from 3 months to a 10 months in 6 cases. In these cases the CT scan allowed as to determine that the integration of the bank bone with the receiver took place after 3–4 months, while the check performed at 6 months did not show any peri-metallic lysis and showed that the P.T.S. had perfectly integrated with the metaepiphysis. No cases of nervous or vascular secondary lesions were detected. No infections, either superficial or deep, were noticed even after a long period.

Discussion: The best surgical treatment of three- or four-part, dislocation and unclassifiable complex fractures of the humerus is still debated, the results achieved with other system or a shoulder prosthesis are not constant. The Authors report a new system consisting of a prismatic threeangular titanium structure which, allows to modulate the reduction of the parts and open a window from the fracture rim through which the surgeon can directly observe the lesion and the relevant parts.

K. Lunsjö A. Tadros J. Czechowski F. Abu-Zidan

Background: We aimed to study the relationship between the number of fractured scapular regions, and the severity and distribution of associated injuries in blunt trauma patients.

Methods: 107 consecutive patients with fractured scapulae (100 males) with a mean age of 35 (8–65) years were prospectively studied between January 2003 and December 2005. Mechanism of injury, associated injuries, injury severity scale (ISS) and the number of anatomical scapular regions involved in each fracture were studied. Patients were divided into single-region, two-region fracture, and more than two-region fracture groups. Computer tomography was used for fracture classification in 99 patients and plain X-rays in the remaining 8.

Results: Road traffic collisions were the most common cause of scapular fracture. 95 patients (89%) sustained associated injuries. The most frequent was chest injury (68 (64%)). The median ISS was 9 (4–57) for the single-region fracture group (n 55), 20 (4–59) for the two-region fracture group (n 30), and 22.5 (4–54) for more than two-region fracture group (n 22) (p=0.02, Kruskal Wallis test). The median values of abbreviated injury scale (AIS) for chest injuries for the three groups were 1 (0–4), 3 (0–5) and 3 (0–5), respectively (p=0.001, Kruskal Wallis test). The single-region fracture group had significantly less posterior structure injury (9/55) compared with the multiple-region fracture group (46/52) (p=0, Fisher’s exact test).

Conclusion: Associated injuries are common in patients having scapular fractures. ISS and AIS for chest injuries are higher and posterior structure injuries more frequent in patients with fractures involving multiple scapular regions.

A. Akiki Y. Arlettaz

Proximal humerus fracture treatment remains controversial. If the conservative treatment is widely accepted for Neer I and Neer II fractures, the attitude is not very clear concerning Neer III and Neer IV fractures.

Several methods are proposed in the literature varying from suturing, pinning or plating the proximal humerus. Hemiarthroplasty are even considered.

In our study we present our results of an internal fixation procedure for 3 part or 4 part fractures of the upper part of the humerus.

Material and Methods: Antegrade nailing with self stabilizing screws, by T2 nail, is used in 13 patients treated between January 2004 and December 2005. Average age is 81 years old. The medial insertion technique is used because of the greater tuberosity fracture. Clinical and radiological data were available for the 13 patients with a mean follow up of 19 months. Functional outcome is assessed using the Visual Analog Scale (VAS) and the Constant Score.

Results: At last follow up, most of the patients are satisfied with their operation with a mean VAS of 2.46 and a mean Constant Score of 64.7. Mean antepulsion was 148° while mean abduction was 136°. No infection was reported. There are 4 cases of greater tuberosity necrosis without influence on the rotator cuff muscles. One case of head necrosis is signaled.

Discussion: Complex fractures of the proximal humerus remain a challenge for the orthopedic surgeons. To date, there is non agreement on the most appropriate osteosynthesis method and the results of shoulder arthroplasty or proximal plating remain controversial. The T2 nail appears to be a simple and reproducible method of achieving reduction, stability and early mobilization. It is an attractive alternative to shoulder prosthesis or proximal plating in trauma victims with complex displaced fractures.

S. Cerciello F. Visci F. Pezzillo G. Maccauro F. Di Gregorio T. Nizegorodcew

Introduction: Antegrade intramedullary locked nailing is a reliable method for the treatment of humeral shaft fractures. There is a still debate on the functional effect due to a possible damage during surgical approach of the rotator cuff, but in the Literature few paper deal with the analysis of tendons in these patients. Ultrasonography is still considered a reliable method in evaluating rotator cuff tendons. The aim of this study is to evaluate if antegrade intramedullary nailing may induce a possible damage on rotator cuff.

Methods: Between May 2002 to December 2005 42 patient suffering of humeral shaft fractures were surgically treated with Unreamed Humeral Nail. Of them 21 (13 males and 8 female) were followed (average follow-up 22,9 months). All the fractures were traumatic except 1 due to bone metastasis of carcinoma. Follow up was clinical with Constant Score, radiographic in 3 projection (neutral, internal and external), and ultrasonographic, evaluating tendon of m. Sovraspinosus.

Results: Healing of fractures was obtained after 2 month from surgery in all cases; Constant Score’s average was 77,0. Three cases of impingement syndrome due to excessive length of nail were observed, healed after the nail removal. Ultrasonography showed that in 13 cases rotator cuff was normal. In 5 cases we have found a signicative hyperecogen area, related to the scarf. We have never had a damage of tendon in all its tickness.

Conclusion: Our study confirms that antegrade intra-medullary nail is a reliable method for the treatment humeral shaft fractures, not adversely influenced shoulder tendons. Damage of rotator cuff observed in few cases is not related to surgical technique, but depends on surgical pitfall with an excessively long nail and then impingement syndrome.

Full Access
M. Fox S. Lambert R. Birch

To review the outcome of compound injury to the shoulder in which traumatic anterior dislocation is associated with concomitant rotator cuff tear and injury to the brachial plexus.

22 patients initially treated at the Peripheral Nerve Injury Unit since 1994 were reviewed from notes, telephone and clinically (n=13) where possible. 19 men and 3 women of average age 53 years were treated with a minimum 3-year follow up. All patients underwent exploration of the brachial plexus and nerve repair where required (graft n=5). Patients had either proven large cuff tear (n=13) or avulsion fracture of greater tuberosity with cuff injury (n=9). 7 of 13 cuff injuries and 7 of 9 tuberosity fractures had been repaired. Nerve injury at exploration was to circumflex (n=20), supra-scapular (n=12), musculocutaneous (n=6), or at the cord level (Posterior n=10, Lateral n=7 Medial n=8). Outcome measures were Berman pain score, sensation, muscle power (MRC grade), abduction, functional scores (Mallett and DASH) and return to work. Statistical analysis used tests for non-parametric data.

22 patients had exploration of the plexus. Most patients did not have an isolated nerve lesion (n=4). Increased depth of nerve lesion correlated with poorer functional outcome. E.g. for circumflex nerve injury (n=18), conduction block (n=8) vs. axonotmesis or neurotmesis (n =10) functional range of movement as assessed by Mallett score was significantly different; Mann Whitney U test p=0.043. Late exploration of nerve tended to correlate with poor outcome, as did late repair of rotator cuff, but not to statistical significance.

Our explorations have shown the nerve injury sustained in these patients to be more widespread than expected. We believe early exploration is vital to give an accurate diagnosis and predict outcome for the nerve lesion. This is particularly important in the presence of associated cuff injury where early repair confers favourable outcome.

I.M. Majid T. Ibrahim M. Clarke C.J. Kershaw

Aims: To investigate the effect of age and occupation on the outcome of carpal tunnel decompression.

Patients and Methods: A total of 271 patients undergoing primary carpal tunnel decompression by a single surgeon were studied. Patients with inflammatory joint disease, thyroid disease and diabetes mellitus were excluded. Outcome was assessed using the Levine-Katz carpal tunnel questionnaire at two weeks preoperatively and six months postoperatively. Cases were divided into six age groups (less than 40 years of age, 40 to 49, 50 to 59, 60 to 69, 70 to 79, and over 80 years of age) and 12 occupational groups according to the International Standard Classification of Occupations (ISCO-88). Statistical analysis was performed using one-way analysis of variance (ANOVA) and post ad-hoc analyses.

Results: Overall there was an improvement in total Levine scores in 269 (99.3%) patients (mean change 33.1, 95%CI: 31.5 to 34.7). This change was greatest in those over 80 years of age (mean 35.8, 95%CI: 29.0 to 42.6) and in those who were service or sales workers (mean 39.6, 95%CI: 34.9 to 44.2), and least in the 70–79 age group (mean 30.7, 95%CI 25.7 to 35.8) and craft and trade workers (mean 29.8, 95%CI: 21.8 to 37.9). Patients reported a greater improvement in symptoms (mean score change 21.4, 95%CI: 20.2 to 22.2), than function (mean 12, 95%CI: 11.1 to 12.7). We found no significant difference in the total, functional or symptomatic Levine score changes between the six age groups (p=0.05) and the 12 occupation groups (p=0.05) following carpal tunnel decompression.

Conclusion: Almost all patients improved after carpal tunnel decompression. However, we found no influence of age and occupation on the outcome of carpal tunnel decompression in our series of patients.


INTRODUCTION: Median Nerve has small vessel on the volar aspect of the nerve which is filled with blood and results in so called ‘ BLUSHING’ of the nerve once it has been decompressed. It was thought that the nerve which didnot blush meant an inadequate decompression was carried out.

PURPOSE: To evaluate whether ‘Blushing’ of the Median Nerve is correlated with adequate decompression and level of recovery in Carpal Tunnel Syndrome through Mini Palmar Incision.

METHODS & MATERIALS: Retrospective analysis of a Single Surgeon practise where it was documented in operation notes whether the nerve was seen to ‘Blushed’ at the time of surgery.They were assessed postoperatively from notes for complete resolution of symptoms and whether there was any recurrence of symptoms.

RESULTS: n=330 Carpal Tunnel Decompressions were reviewed. It was noted that those who had complete resolution of symptoms had ‘Blushing’ noted at the time of surgery compared to those who had partial or incomplete resolution of symptoms wher ‘No BUSHING’ was noticed. Average time of follow up = 6 weeks. Blushing Noted at the time of decompression 192, Recovery/ improvement of symptoms 189, Blushing not noted at the time of surgery 38, NO documentation about Blushing in 100

CONCLUSION: Blushing of Median Nerve intraoperatively is a reliable sign for complete decompression of the nerve and is correalted with good final outcome.

R.S. Gaheer A. Ratnam

Carpal tunnel syndrome is a common condition with a prevalence of 2.7% based on symptoms, clinical signs, and neurophysiology. The procedure to cure these patients, whether it is open or endoscopic, is usually successful in returning sensation, abolishing numbness and paraesthesiae, and improving manual dexterity. However, as many as 14%–32% of patients may have persistent symptoms

The general treatment of patients with recurrent carpal tunnel syndrome is re-exploration of the median nerve and neurolysis. Various procedures have been described to cover the median nerve with muscle or fat tissue. These include–external neurolysis, local muscle flaps, fat grafts and flaps, vein wrapping and synovial flaps. The outcome of secondary carpal tunnel surgery is only fair and many procedures are possible.

In 19 patients presenting with recurrent carpal tunnel syndrome over a period of five years, silicone sheath was used to cover the median nerve following neurolysis. All of these 19 cases were performed by the senior author (ASR).

We audited the results of this procedure using the carpal tunnel outcome instrument (Levine et al., 1993) for subjective assessment and grip strength, thumb key pinch force and two point discrimination sensation for Objective assessment. 17 patients were followed up for the purpose of this study. 2 were lost to follow up. Twelve patients were satisfied with their outcomes and were prepared to undergo the surgery again or recommend it to others (more than 70%). However, two were dissatisfied and three were uncertain of their feelings.

T. Taneja N. Ellahee R. Patel B. Ollivere D. Nairn J. MahaluxmiVala P. Achan S. Curry D. Goodier

Carpal Tunnel Syndrome is the most common entrapment neuropathy encountered in clinical practice. Previous studies have suggested that the disease has a higher prevalence in the elderly(Stevens JC etal, Neurology 1988;) and that this sub group also tends to have a higher prevalence of severe CTS.(Seror P, Ann Hand Surg 1991; Bland etal, J Neurol Neurosurg Psychiatry). Surgical decompression of the median nerve is the treatment of choice with a reported success rate of between 53 and 97 %.(Katz et al, J Hand Surg 1998).

There has been some controversy regarding the effectiveness of surgery in elderly patients. The aim of our study was to evaluate the results of carpal tunnel release in patients over the age of 75 years at the time of surgery. A literature search revealed few studies carried out in elderly patients–Weber etal-(mean age 75 years), Porter etal (mean age 59.8 years) and Leit et al (mean age 79 years). The average age of our patient group (80.4 years) is the highest reported in literature so far.

We posted questionnaires to all patients who were over 75 years at the time of their surgery. There were a total of 49 patients (65 hands) operated over the last 10 years who belonged to this age group. We used the Brigham And Women’s Hospital Questionnaire devised by Levine et al. (1993). In addition, we added some questions to assess patient satisfaction with the procedure. 65% of the patients were females. The average age was 80.4 years.

The completed questionnaires were used to calculate the Pre and Post operative scores. The mean pre operative score was found to be 3.18, which improved post operatively to 1.8. (Scale of 1 to 5, with 1 being the best and 5 the worst). Importantly, although all symptoms improved, some such as pain and numbness showed a much greater improvement than grasping power. On the Visual Analogue Scale, pain scores improved from 6.4 to 2.3 post surgery. 82 % of patients had no scar tenderness, 12 % had mild to moderate tenderness, while 6 % reported severe scar tenderness. Overall 79% of patients showed improvement, 15 % felt that the surgery had made no difference, while 6% reported worsening of their symptoms after surgery.

Our study showed that 8 out of 10 elderly patients will improve after carpal tunnel release, though all symptoms are unlikely to improve. The symptom least likely to improve is weakness of the hand. The results of this study are important to counsel this sub group of elderly patients, so that they may take an informed decision on whether to proceed with the surgery.

A. Kapoor I. Rafiq P. Harvey R. Murali

INTRODUCTION: CTS is the most common nerve entrapment syndrome. Repeated flexion and extension activities of the wrist coupled with certain finger flexion causes oedema and compression of the median nerve within the carpal tunnel of the wrist. Several treatment options, both conservative and surgical are available to relieve the pressure on the median nerve. Although studies support the efficacy of splinting for CTS the length of splinting, type of splints, day or night use and the effects on other variables are still less agreed.

MATERIALS AND METHODS: A Randomised control trial with subjects randomised to a splint and a control group. 44 patients(60 hands) evaluated at recruitment, 2,8 and 12 weeks. Difference in Levine’s symptom and functional severity scores, between the two groups, used as the primary outcome measure.

STATISTICAL METHODS: Repeated measure analysis(ANOVA) and paired t test used for statistical analysis between the two groups.

RESULTS: There was no difference between the two groups at baseline. Improvement in symptom severity score in the splinted group at the end of 12 weeks(p< 0.05). No difference in functional severity between the two groups.

CONCLUSION: Splintage helps to improve symptoms related to carpal tunnel syndrome in a short term period. This is the duration that the patients referred by GP’s have to wait before seeing a hand specialist. Hence they can be treated with splints during this period to give them symptomatic relief.

V. Psychoyios F. Villanueva-Lopez K. Dakis P. Kinnas

Aim: To retrospectively review the results of the use of adductor digiti quinti flap in failed cases of primary carpal tunnel tunnel release. The concept under this procedure is to provide a highly vascularised bed for axonal regeneration.

Material: Twenty cases of failed carpal tunnel release included in the study. The average age of patients was 43 years. There were thirteen female and five male patients. In two cases, one male and one female the procedure performed bilaterally.

All patients had a repeat of release ading a neurolysis of the median nerve. The adducor digiti quinti flap was dissected up to its neurovascular bundle and flipped over..

Results: In thirteen cases the procedure was successful as this was detected objectively and subjectively. In four cases the situation was unchanged and in three a revision surgery required for decompression of the nerve. Complex regional pain syndrome developed in three cases.

Conclusion: Although postoperative healing and rehabilitation time is lengthy due to more extensile dissection, pain relief, motor and sensory improvement, and hand dexterity justify the procedure.

P. Haentjens D. Verheughe

Background: A recent change in the Belgian law lead to the obligation of evaluating the musculoskeletal system among employees using visual display terminal (VDT) during the routine annual visit. We conducted a cross-sectional study to determine prevalence of and risk factors for musculoskeletal symptoms (MSS) and disorders (MSD) in general, and carpal tunnel syndrome (CTS) in particular.

Methods: During the routine annual visit all VDT employees of different kinds of companies and occupations were asked about upper extremity MSS by their occupational physician. Participants who met the criteria for MSS within the last month were physically examined in search of a MSD in general, and CTS in particular. Prevalences were calculated, and key risk factors for MSS and CTS were determined using logistic regression analyses.

Results: The total prevalence of any upper extremity MSS among 1087 VDT-employees was 31.3%. Neck symptoms (21.6%) were the most frequently reported, followed by shoulder (21.6%), elbow/forearms (4.1%), hands/wrists (7.3%), and finger (5.2%) symptoms. The prevalence of CTS depended on the diagnostic criteria used: 1.8% for symptom-specific CTS (typical anatomical distribution of numbness and paresthesias), 1.2% for examination-confirmed CTS (at least one positive provocative test, Tinel’s nerve percussion test or Phalen’s wrist flexion test), and 0.2% for electrophysiologically-confirmed CTS (abnormal nerve conduction tests). Logistic regression analyses identified increasing age, female gender, the duration of professional VDT use per day, a history of thyroid diseases, and a history of rheumatoid arthritis as significant and independent factors associated with MSS. Adaptation of the work-place was associated with a lower likelihood of MSS. Only increasing age and female gender were identified as significant and independent factors associated with CTS (symptom-specific and examination-confirmed CTS). Job-related factors were not significantly associated with an increased risk for CTS.

Conclusions: Our study confirms the high prevalence of MSS among Belgian visual display terminal users (more than 30%). Two work-related factors were clearly associated with MSS: the duration of professional VDT use per day (increased risk) and prior adaptation of the workplace according to advice given by the occupational physician (decreased risk). By contrast, the prevalence of CTS was low (less than 2%), and no job-related risk factors for CTS could be identified among VDT users.

S. Joshy S.C. Deshmukh B. Thomas

Aim: Osteoarthritis of the wrist is a well recognised cause of secondary carpal tunnel syndrome. The aim of the study is to compare the outcome following carpal tunnel decompression with regard to patient satisfaction. We compared the outcome of carpal tunnel decompression between patients with and with out osteoarthritis of the wrist.

Patients and Methods: The study was done retrospectively. Clinical notes of all the patients who underwent carpal tunnel decompression over a period of 8 years were verified. Twenty four patients who underwent surgical decompression for carpal tunnel syndrome secondary to osteoarthritis were identified by reviewing the notes and the radiographs. Control group consisted of 24 patients who under went carpal tunnel decompression but without osteoarthritis of the wrist. The control group was matched for age, sex, side, and neuro-physiological severity of the nerve compression. Clinical notes were verified to find whether the patients were satisfied with the symptom relief at the first post-operative follow up visit.

Results: There were 24 patients in the group with osteoarthritis of the wrist. The mean age of the patients was 71 years (range 33–89 years). There were 19 females and five males. The right hand was involved in 17 patients and the left was involved in 7 patients. The control group with out osteoarthritis also had similar distribution regarding age sex side, and neuro-physiological severity of nerve conduction. In the group with osteoarthritis of the wrist 17(71%) patients reported the their symptom relief as satisfactory and the rest seven(29%) reported the results as unsatisfactory. In the control group 23(96%) patients reported their symptom relief as satisfactory and one (4%) reported their results as unsatisfactory (P= 0.0325).

Conclusions: Patient satisfaction following surgical decompression in patients with secondary carpal tunnel syndrome due to osteoarthritis is significantly lower compared to patients with out osteoarthritis of the wrist. Patients with osteoarthritis of the wrist should be warned about the higher incidence of poor outcome prior to decompression.

A. Mallick M. Clarke C.J. Kershaw

The purpose of the study was to evaluate if 2 week Levine score can provide an adequately responsive outcome measure in Carpal Tunnel Decompression by comparing it with 6 month score.

The treatment outcome of 300 patients with Carpal Tunnel Decompression was determined by using Levine score at 2 weeks and 6 months after surgery. The mean age of patients was 55 years and 6 months, 71.3% (214) were female with 55.33% (167) operations being performed on right hand. All patients were scored through Levine questionnaire pre operatively and at 2 weeks and 6 months from date of surgery. The correlation between the scores was evaluated.

Although statistical significance was found between the pre operative score and the scores at both 2 weeks and 6 months, no statistical difference was found between the scores at 2 weeks and 6 months post surgery. Multiple regression analysis with the 2 week–6 month score difference as the dependable variable shows a predictable outcome at 2 weeks.

We conclude that the Levine score at 2 weeks is a reliable, responsive and practical instrument for outcome measure in Carpal Tunnel Surgery. It coincides with suture removal and provides a convenient and predictive assessment of the medium term results in a high percentage of treated patients.

M. Costa U. Prakash P. Forguet

Background: Hip resurfacing preserves bone stock on the femoral head. Some authors believe that this is at the expense of sacrificing more bone on the acetabulum and they point out two main reasons for this. Since resurfacing tends to be used in younger and more active individuals a larger head to neck ratio seems desirable in order to provide a better range of movement before impingement. In addition, the acetabular component has to be a minimum of 5 mm thick to prevent deformation on implantation and the subsequent compromise in the congruency of the bearings.

Method: We report the average size of the acetabular components of 220 Cormet resurfacings and 199 Pinnacle cups implanted in our department over a period of 18 months. From these sizes we estimated the mean acetabular bone loss for each procedure.

Results: The mean cup size was 53.7 mm for Cormet and 54.1 mm for Pinnacle i.e. the acetabular component of the resurfacing was smaller than the equivalent uncemented total hip replacement.

Conclusions: These figures show that resurfacing arthroplasty does not necessarily lead to greater acetabular bone loss than a total hip replacement. In our practice, we concentrate upon preserving acetabular bone rather than establishing a large head to neck ratio. In spite of this approach, the occurrence of impingement and dislocation among our patients seems to be as rare as in other comparable series.

R. Steffen K.S. O’Rourke J.P. Urban H.S. Gill D.J. Beard P. McLardy-Smith D.W. Murray

Introduction: Avascular necrosis of the femoral head after resurfacing hip replacement is an important complication which may lead to fracture or failure. We compared the changes in femoral head oxygenation resulting from the anterolateral approach to those resulting from the posterior approach.

Methods: In 22 patients undergoing hip resurfacing surgery, a calibrated gas-sensitive electrode was inserted supero-laterally in the femoral head via the femoral neck following division of the fascia lata. Inter-operative X-ray confirmed correct electrode placement. Baseline oxygen concentration levels were recorded immediately after electrode insertion. All results were expressed relative to this baseline, which was considered as 100% relative oxygen concentration. Oxygen levels were monitored continuously throughout the operation. 10 patients underwent surgery through the posterior approach, 12 patients through the antero-lateral approach.

Results: During the operation patterns were similar for both groups, except following joint relocation and soft tissue reconstruction; oxygen concentration recovered significantly in the anterolateral group only. The posterior approach resulted in significantly lower (p< 0.01) oxygen concentration at the end of the procedure (22%, SD 31) than the antero-lateral approach (123%, SD 99).

Discussion and Conclusion: The anterolateral approach disrupts the femoral head blood supply significantly less than the posterior approach in patients undergoing resurfacing. The incidence of complications related to avascular necrosis might be decreased by adopting blood supply conserving surgical approaches.

E.T. Davis M. Olsen R. Zdero M. Papini J. Waddell E. Schemitsch

Introduction: We aimed to examine the effect of neck notching during hip resurfacing on the strength of the proximal femur.

Methods: Third generation composite femurs that have been shown to replicate the biomechanical properties of human bone were utilised. Imageless computer navigation was used to position the initial guide wire during head preparation. Six specimens were prepared without a superior notch being made in the neck of the femur, six were prepared in an inferiorly translated position to cause a 2mm notch in the superior femoral neck and six were prepared with a 5mm notch. All specimens had radiographs taken to ensure that the stem shaft angle was kept constant. The specimens were then loaded to failure in the axial direction with an Instron mechanical tester.

A three dimensional femoral finite element model was constructed and molded with a femoral component constructed from the dimensions of a Birmingham Hip Resurfacing. The model was created with a superior femoral neck notch of increasing depths.

Results: The 2mm notched group (mean load to failure 4034N) were significantly weaker than the un-notched group (mean load to failure 5302N) when tested to failure (p=0.017). The 5mm notched group (mean load to failure 3121N) were also significantly weaker than the un-notched group (p=0.0003) and the 2mm notched group (p=0.046). All fractures initiated at the superior aspect of the neck, at the component bone interface. The finite element model revealed increasing Von Mises stresses with increasing notch depth.

Discussion: A superior notch of 2mm in the femoral neck weakens the proximal femur by 24% and a 5mm notch weakens it by 41%. This study provides biomechanical evidence that notching of the femoral neck may lead to an increased risk of femoral neck fracture following hip resurfacing due to increasing stresses in the region of the notch.

R.M. Gillies M. Hogg S.M. Donohoo L. Kohan

Introduction: The process of impacting cemented hip resurfacing components may, in part, be associated with femoral neck fracture. The impaction process may introduce fractures due to the impact shock wave passing through the bone during the setting of the implant and achieving a completely seated position. The aim of this study was to measure the impaction loads during hip resurfacing surgery and correlate the measured loads to theoretical calculations.

Methods: Following ethical approval 3 patients have been enrolled out of 24 patients in a pilot study. A surgical mallet was manufactured and instrumented with a calibrated impact load cell. During the impaction procedure the impact loads are recorded to a laptop using Labview software. An Excel spreadsheet has been written using the finite difference method to calculate the impact loads based on a mass (hammer, impactor and implant) and spring system (compression only) defining each part of the surgical instrumentation used to impact the resurfacing component onto the femoral head.

Results: Clinically, upto 19 impacts are used to seat the resurfacing implant onto the femoral head. Loads upto 24kN were recorded. The finite difference model was calibrated to the clinical measurements. The Pearson’s R correlation coefficient for the net force on the mallet was 0.91 and for the impulse was 0.98

Discussion: This study has investigated the clinical impaction loads imparted onto an implant during resurfacing surgery and developed a finite difference model of the process. The finite difference approach can be used to better understand the loads applied to not only the implant, but the underlying bone. This may, in part, give the surgeon a better understanding as to whether the bone has been predisposed to fracture following the high impact loads and thereby affecting the long-term integrity of the joint replacement.

The purpose of this study was to evaluate early results of a new, as yet undescribed, minimally invasive, gluteus maximus splitting posterior approach for metal on metal (MOM) hip resurfacing. Surgical approach is described, backed with a video of the procedure. Results of the first 100 cases are presented.

A new, minimally invasive, gluteus maximus splitting approach is described. The single incision approach allowed MOM hip resurfacing to be carried out through an incision ranging 8.25 ± 2.25cm. Release of gluteus maximus insertion to femur is not necessary. Intra-operative fluoroscopy is not necessary. Special acetabular reamer handle and acetabular impactor had to be used for accurate acetabular component placement. Femoral neck targeting device, suitable for minimally invasive surgery was used for accurate placement of femoral neck centring pin. This allowed for accurate placement of femoral component

Results of 100 patients who had undergone MOM hip resurfacing are presented: Average review was 2 years, range 22–46 months. Average age of patient was 57 years; range 55 ± 22 years. Average BMI was 27; range 29.95 ± 11.85. Average blood loss was 270ml; range 450 ± 350ml. Average incision was 8cm; range 8.25 ± 2.25cm. Operation time was no longer than conventional open posterior approach. Early discharge at day 3, post-op was possible and patients were able to walk without aids at 3 weeks, post-op. There were no cases of infection, nerve damage, dislocation or malposition of implant. There was no case of hypertrophic bone formation. There was one fracture neck of femur at 6 weeks post-op.

Minimally invasive hip resurfacing can be carried out successfully using a new gluteus maximus splitting approach with excellent early results and no complications apart from 1% risk of fracture neck of femur.

R.M. Gillies M. Hogg L. Kohan

Introduction: Cemented hip resurfacing component orientation may, in part, be associated with femoral neck fracture. Orientation offset may be introduced due to the cement setting prior to achieving a completely seated component. Varus/valgus orientation error may occur due to surgical error or poor instrumentation design. We modeled a number of different orientations and investigated bone mineral density change using the finite element method.

Methods: CT scans were used to reconstruct the femoral geometry and create a finite element model. The boundary conditions applied were hip muscle forces at the 45% position of the gait cycle. Two models were created, a preoperative (reference) and a postoperative (reconstructed) model. The post operative model was reconstructed using the Birmingham Hip Replacement (BHR). Implant offsets and varus/valgus orientations were analysed. The bone mineral density (BMD) changes at nine positions along the superior and inferior aspects of the alignment stem were analyzed.

Results: Results suggest bone loss decreases with increasing offset distances. Femoral offset distance is defined as the perpendicular distance from the center line of the femoral shaft to the center of the femoral head. Greater femoral stem offsets increases the abductor moment arm and this decreases the abductor force need for walking as well as the overall articulating reactive force at the articulating surface. As the BHR orientation deviates away from the an extreme valgus to a more varus position, the volume of bone that will decrease in BMD increases.

Discussion: There is minimal difference between the 1mm and 3mm offsets and their respective bone remodeling volumes. The 5mm offset has a larger bone volume where the BMD will increase; this is due to the larger moment applied to the proximal femur and is not an advisable surgical position as there may be a large density gradient at the mouth of the resurfacing component and could predispose the femoral neck to fracture. There is also not a lot of difference in bone remodeling volume between the extreme valgus, 5° and 10° cases. However, the extreme valgus case does present a “notching” risk. The objective of this study was to implement a consistent theoretical adaptive bone remodelling rule that may, in part, give an understanding as to how a femoral resurfacing component’s orientation would influence and simulate BMD changes in the proximal femur.

C. Heisel D. Schneider M. Menge J. Kretzer

Introduction: Aim of the study was to give an overview about the main macro- and microstructure differences of commercially available resurfacing hip implants. The effect of the manufacturing process and the subsequent heat treatment leads to variable microstructures of implant materials. It is undisputable that a low surface roughness and high sphericity improves the wear behaviour. But the radial clearance, the manufacturing process and heat treatment are discussed controversially.

Methods: Resurfacing hip implants with a 46mm head diameter and corresponding cups were analyzed. Commercially available hip resurfacing implants from 10 different manufacturers were included in this investigation. The heads and cups were measured in a coordinate measuring machine (Mahr Multisensor MS 222). A best fit sphere was created from the point clouds and evaluated using analysing software (Imageware 12.1, UGS Corp.). Head and cup radial clearances were measured and sphericity deviation calculated and graphically plotted. Measurements on surface roughness were carried out three times per implant (Mahr Pertometer M2). The microstructures of the heads and cups were inspected by SEM (LEO 440). Surface images were taken using the scanning electron mode. The back scatter electron mode was used to get element weighted images.

Element analysis was performed by EDX (Oxford D. 7060) to identify carbides and the alloy composition. Element distribution maps were taken to separate the single elements.

Results: The mean radial clearance was found to be 85.53μm. The range was from 49.47μm to 120.93μm. We classified all implants into three groups (low, midrange and high clearance). The low clearance group ranged from < 50μm to 75μm, midrange from 75μm to 100μm and high clearance from 100μm to > 125μm.

All implants showed a sphericity deviation less than 10μm. On average the heads tended to have a higher spherical deviation of 4.1μm (SD: 2.3μm) compared to the cups 2.7μm (SD: 1.4μm). Based on the SEM and EDX inspection the manufacturing process, heat treatment and carbide distribution could be clarified.

Discussion: This study gives an overview about the main macro- and microstructure differences of commercial available resurfacing hip implants.

The characteristically unspheric formations of the heads may be due to the cooling process after manufacturing the implant and there is also a relation between the wall thickness of the implant and the unspheric formations. With decreasing wall thickness the implant cools faster locally. Additionally a cup with a thin wall may deform under loading condition and a very tight clearance could be detrimental.

This study will help to understand clinical observations. It still has to be proven that these biomechanical factors influence the clinical performance of hip resurfacing implants.

M. Costa H. Amarasekera U. Prakash P. Forguet S. Krikler D. Griffin

Introduction: Two major complications of hip resurfacing arthroplasty are avascular necrosis of the femoral head and femoral neck fracture. Both are thought to be precipitated by disruption of the blood supply to the femoral head and neck during the approach to the hip joint. Ganz et al have described their technique of approaching the hip joint using a “trochanteric flip” osteotomy. This has the theoretical advantage of preserving the medial femoral circumflex artery to the femoral head. The aim of this study was to compare the intra-operative femoral head blood flow during the Ganz flip osteotomy to the blood flow during a posterior approach for resurfacing arthroplasty of the hip.

Methods: The intra-operative measurements of blood flow were performed using a DRT laser Doppler flow-meter with a 20 mW laser and a fibreoptic probe. The probe was introduced into the lateral femoral cortex and threaded into the femoral head under image intensifier control. Measurements were recorded before the approach to the hip was performed, after the approach was performed but before the head was dislocated, and after the head was dislocated.

Results: Our initial results indicate that there is on average a 50% drop in the blood flow to the femoral head after a posterior approach to the hip joint. In contrast, the trochanteric flip osteotomy produces a much smaller fall of around 18%. We have used these results to inform a sample size calculation, and are currently recruiting further patients to achieve a total of 42 in order to confirm a statistically significant effect.

Conclusion: The Ganz trochanteric flip osteotomy appears to produce less damage to the blood supply to the femoral head during resurfacing arthroplasty than the posterior approach. This study will inform surgeons in deciding on their preference for a routine approach for hip resurfacing.

H.C. Amstutz M.J. Le Duff F.J. Dorey

Introduction: The purpose of the present study was to assess the clinical results of metal-on-metal hip resurfacing for the treatment of hip arthrosis in patients with a BMI of 30 or more.

Materials and Methods: From a consecutive series of over 1000 Conserve® Plus metal-on metal hybrid resurfacings, 148 hips were resurfaced in 138 patients with a BMI of 30 or more at the time of surgery. Average age was 49.4 years (range, 18 to 72) with 88% male. The average weight was 104.6 kg (range 74 to 164) and average BMI 33.4 (30.0 to 46.4). “Idiopathic” OA was the dominant etiology with 80.0%. The femoral metaphyseal stem was cemented in 43 hips and press-fit in the remaining 105. All acetabular components were press-fit.

Results: Average follow-up was 6.2 years (range, 2.0 to 10.2). UCLA hip scores improved significantly (pain: 3.5 to 9.4; walking: 5.9 to 9.5; function: 5.4 to 9.2; activity: 4.3 to 7.1). There were no cases of acetabular or femoral component loosening. 2 hips (1.4%) were revised, 1 for femoral neck fracture and one for acetabular cup protrusio the day after surgery in a bilateral patient with poor bone quality. 3 hips (2.0%) have radiolucencies about the femoral stem. All are asymptomatic and none have progressed for an average of 5.2 years (range 4.5 to 6.8). There were no revisions for any reason and no radiolucencies observed in patients with a BMI of 35 or more (n=27).

Conclusions: Metal-on-metal resurfacing arthroplasty of the hip is performing extremely well in patients with high BMI, in contrast with the results of conventional THR. These results are in agreement with our previous finding that weight is protective of prosthesis durability with resurfacing. This could be explained by a greater fixation area on the femoral side, a greater bone mineral density, and a slightly reduced (but still high) activity level in this patient population compared to patients with a BMI less than 30 (7.1 vs 7.6, p=0.002).

C. McBryde K. Dhene A. Pearson P. Pynsent R. Treacy

Metal-on-metal hip resurfacing is increasingly common. Patients suitable for hip resurfacing are often young, more active, may be in employment and may have bilateral disease. One-stage bilateral total hip replacement has been demonstrated to be as safe as a two-stage procedure and more cost effective. The aim of this study was to compare the in-patient events, outcome and survival in patients undergoing one-stage resurfacing with a two-stage procedure less than one-year apart.

Methods. Between July 1994 and August 2006 a consecutive series of 93 patients underwent bilateral hip resurfacing within a year. 34 patients in the one-stage group. 44 patients in the two-stage group. The age, gender, diagnosis, ASA grade, total operative time, blood transfusion requirements, medical complication, surgical complications, length of stay, duration of treatment, revision and Oxford hip scores were recorded.

Results. There were no significant differences in age, gender, ASA grade between the one-stage and the two-stage. There were 4 minor complications in the one stage group and 5 in the two-stage group. All patients that suffered a complication made a full recovery. There was no significant difference in the blood transfusion requirements. The mean anaesthetic time was 136 minutes in the one stage group and 92 minutes in the two-stage group with a significant mean difference of 44 minutes(95% c.i. 31–52). The mean total length of hospital stay was 11 days in the one-stage group and 16 days in the two-stage group with a significant mean difference of 5 days(95\% c.i. 4.0–6.9). The mean difference in length of treatment time of 6.5 months was significant(95\% c.i. 4.0–9.0).

No patients have undergone a revision procedure during the study period and no patient is awaiting revision surgery.

Conclusions. This study demonstrates no detrimental effects when performing a one-stage bilateral metal-on-metal hip resurfacing in comparison to a two-stage procedure. There are advantages of a one-stage procedure over a two-stage procedure for bilateral disease. Total hospital stay is reduced by 31.3% and the mean length of treatment is reduced by 50.0%. These benefits do not appear to come at the cost of increase complications. The complication rate in both groups was very low and all of the complications were short-term and are unlikely to have any bearing on the longevity of the prosthesis.

E.T. Davis P. Gallie K. Macgroarty J. Waddell E. Schemitsch

Alignment of the femoral component during hip resurfacing has been implicated in the early failure of this device. Techniques to facilitate a more accurate placement of the femoral component may help prevent these early failures. We aim to establish whether the use of imageless computer navigation can improve the accuracy in alignment of the femoral component during hip resurfacing.

6 pairs of cadaveric limbs were randomized to the use of computer navigation or standard instrumentation. All hips had radiographs taken prior to the procedure to facilitate accurate templating. All femoral components were planned to be implanted with a stem shaft angle of 135 degrees. The initial guide wire was placed using either the standard jig with a pin placed in the lateral cortex or with the use of an imageless computer navigation system. The femoral head was then prepared in the same fashion for both groups. Following the procedure radiographs were taken to assess the alignment of the femoral component.

The mean stem shaft angle in the computer navigation group was 133.3 degrees compared to 127.7 degrees in the standard instrumentation group (p=0.03). The standard instrumentation group had a range of error of 15 degrees with a standard deviation of 4.2 degrees. The computer navigated group had a range of error of only 8 degrees with a standard deviation of 2.9 degrees.

Our results demonstrated that the use of standard alignment instrumentation consistently placed the femoral component in a more varus position when compared to the computer navigation group. The computer navigation was also more consistent in its placement of the femoral component when compared to standard instrumentation. We suggest that imageless computer navigation appears to improve the accuracy of alignment of the femoral component during hip resurfacing.

H.S. Gill P.A. Campbell A. Sabokbar D.W. Murray K.A. De Smet

Introduction: A major concern with cemented hip resurfacing arthroplasty (HRA) femoral components is the thermal damage to femoral head during cement curing; this maybe linked to fracture (reported incidence ~2%) and early failure. We investigated the effect of a modifid surgical technique using pulse lavage, lesser trochanter suction and early reduction on the maximum temperature recorded in the femoral head during HRA, compared to manual lavage and reduction after cement curing.

Methods: Patients undergoing total hip replacement (THR) were given a dummy HRA procedure, during which a temperature probe was inserted into the femoral head and the measuring tip placed close to the reamed surface; the position of the probe was confirmed by inter-operative xray. Four subjects received a dummy HRA femoral component using manual lavage and Simplex cement. The implanted femur was kept dislocated until the cement cured. The implanted heads were then removed and sectioned to locate the temperature probes, the THR surgery was then performed. Five patients receiving a definitive HRA were also measured; for these subjects suction on the lesser trochanter was used, pulse lavage given for 30 seconds prior to cementing with Simplex, and pulse lavage of the femoral head for 2 minutes, applied 1 minute after cementing the femoral component. The implanted joint was then immediately reduced and a further two minutes of pulse lavage applied to the reduced joint. Temperatures were recorded until the cement finally cured. In every case the cement was hand mixed for 1 minute and the component implanted at 2 minutes 30 seconds after mixing began.

Results: Sectioning showed that probe tips were < 0.5mm from cement mantle. The maximum temperature recorded in the femoral head was significantly (p=0.014) greater for the manual technique, median value of 47.2°C (37.0 to 67.9°C), than for the pulse lavage technique, median value of 32.7°C (31.7 to 35.6°C).

Discussion: The results show that excessive bone temperatures can occur during hip resurfacing. Temperatures above 45°C kill bone cells, the manual technique may lead to substantial thermal necrosis. Technique modification, with the use of suction on the lesser trochanter, generous use of pulse-lavage and joint reduction prior to cement curing, significantly reduced the temperatures recorded. With the modified technique, the maximum temperatures were well below the threshold of thermal damage. This modified technique is recommended as the potential for thermal bone necrosis is significantly reduced.

R.W. Poolman L.C. Keijser M.C. de Waal Malefijt L. Blankevoort F. Farrokhyar M. Bhandari

Background: The selection of presentations at orthopedic meetings is an important process. If the peer reviewers do not consistently agree on the quality score, the review process is arbitrary and open to bias. The aim of this study was:

1) To describe the inter reviewer agreement of a previously designed scoring scheme to rate abstracts submitted for presentation at the Dutch Orthopedic Association.

2) To test if quality of reporting of submitted abstracts increased in the years after the introduction of the scoring scheme.

3) To examine if a review process with a larger workload had lower inter rater agreement.

Methods: We calculated intraclass correlation coefficients (ICC) to measure the level of agreement among reviewers using the International Society of the Knee (ISK) abstract quality of reporting system. Acceptance rate and quality of the abstracts are described.

Results: Of 419 abstracts 229 (55%) were accepted. Inter-reviewer agreement to rate abstracts was substantial 0.68 (95%CI 0.47, 0.83) to almost perfect 0.95 (95%CI 0.92, 0.97) and did not change over the eligible time period. Less abstracts were accepted after 2004 (p = 0.039). The mean ISK abstract score, maximally 100 points, for accepted abstracts ranged from 60.4 (95%CI 57.7, 63.0) to 63.8 (95% CI 62.0, 65.7). The mean ISK abstract score for rejected abstracts varied from 45.8 (95%CI 40.3, 51.2) to 50.6 (95% CI 46.5, 54.8). Both scores for accepted and rejected abstracts did not change over time. Workload of the reviewers did not influence their level of agreement (p=0.167).

Interpretation: The ISK abstract rating system has an excellent inter observer agreement. Other scientific orthopedic meetings could adopt this ISK rating system for further evaluation in local or international setting.

J. Dettori D. Norvell B. Hanson B. Kopjar

Objectives: An evidence-based trauma database that rated the level-of-evidence for the majority of orthopedic trauma literature would be useful to orthopedic trauma surgeons and researchers. Currently, the development of a database using evidence ratings for such a large body of literature is a time-consuming and expensive endeavor. However, if an accurate rating could be obtained from an abstract without reading the full text, such an endeavor would be feasible. Thus, the purpose of this study is to determine if a reviewer can successfully ascertain the level-of-evidence from the article’s abstract without reading the full text article.

Methods: We compared the level-of-evidence rating obtained from reading an article’s full text with the rating obtained from reading the abstract alone. We reviewed 162 clinical articles published from January 2000 through April 2004 in five orthopedic trauma journals. To establish a full text rating, two reviewers independently rated the full text of each article for study type (therapeutic, prognostic or diagnostic) and level-of-evidence (I through V). The ratings from the two reviewers were compared and disagreements were reconciled through discussion to form a final full text rating. A third reviewer rated the abstracts of each article without access to the full text or full text rating.

Results: Of the 162 articles, 118 (73%) were therapeutic, 40 (25%) were prognostic and 4 (3%) were diagnostic. Most studies represented level IV evidence (65%), with only 15% representing the highest level-of-evidence, level I. Kappa values for agreement between the two reviewers rating the full text were 0.81 for study type and 0.79 for level-of-evidence, and the kappa values for agreement between the final full text rating and the abstract rating were 0.68 for study type and 0.75 for level-of-evidence, respectively. Thirteen of the discordant abstracts (8% of the entire set) lacked sufficient or correct evidence compared with the full text to render an accurate rating.

Conclusion: Accurate study type and level-of-evidence rating in trauma articles can be obtained in most orthopedic trauma articles from reading an article’s abstract alone. Thus, developing an evidence-based trauma database that uses abstracts to rate the level-of-evidence of the orthopedic trauma literature appears feasible and appropriate.

This research was supported by a grant from the AO Foundation, Clinical Investigation and Documentation, Clavadelerstrasse, 7270 Davos Platz, Switzerland

E. Tsiridis Z. Ali A. Bhalla Z. Gamie M. Heliotis N. Gurav S. Deb L. DiSilvio

Impaction allografting is a bone tissue engineering technique currently used in lower limb reconstruction orthopaedic surgery. Our hypothesis was that biological optimisation can be achieved by demineralisation and addition of osteogenic protein-1(OP-1) to the allograft. The objective of our in vitro study was to evaluate human mesenchymal stem cell (MSC) proliferation (Alamar Blue assay, titrated thymidine assay, total DNA Hoechst 33258 and scanning electron microscopy) and osteogenic differentiation (alkaline phosphatase assay) in two types of impacted carrier, namely demineralised bone matrix (DBM) and insoluble collagenous bone matrix (ICBM), with or without OP-1. The objective in vivo was to compare the osteogenic potential of impacted DBM with or without OP-1, with that of impacted fresh frozen allograft (FFA), again with or without OP-1. DBM+OP-1 optimized osteoinduction and significantly improved (p< 0.05) proliferation and differentiation in comparison to the majority of all other graft preparation in vitro. In addition DBM+OP-1 was significantly superior, with regard to osteogenesis, compared to the impacted FFA alone (p< 0.001), FFA+OP-1 (p=0.01) and DBM alone (p=0.02) in vivo. We propose that partial demineralisation and addition of OP-1 provides a good method for improving the osteoinductive properties of fresh allograft currently used in the impaction grafting technique.

R.W. Poolman P.A. Struijs R. Krips I.N. Sierevelt K.H. Lutz M. Zlowodzki M. Bhandari

Background: The Levels of Evidence Rating System is widely believed to categorize studies by quality, with Level I studies representing the highest quality evidence. We aimed to determine the reporting quality of Randomised Controlled Trials (RCTs) published in the most frequently cited general orthopaedic journals.

Methods: Two assessors identified orthopaedic journals that reported a level of evidence rating in their abstracts from January 2003 to December 2004 by searching the instructions for authors of the four highest impact general orthopaedic journals. Based upon a priori eligibility criteria, two assessors hand searched all issues of the eligible journal from 2003–2004 for RCTs. The assessors extracted the demographic information and the evidence rating from each included RCT and scored the quality of reporting using the reporting quality assessment tool, which was developed by the Cochrane Bone, Joint and Muscle Trauma Group. Scores were conducted in duplicate, and we reached a consensus for any disagreements. We examined the correlation between the level of evidence rating and the Cochrane reporting quality score.

Results: We found that only the Journal of Bone and Joint Surgery–American Volume (JBJS-A) used a level of evidence rating from 2003 to 2004. We identified 938 publications in the JBJS-A from January 2003 to December 2004. Of these publications, 32 (3.4%) were RCTs that fit the inclusion criteria. The 32 RCTs included a total of 3543 patients, with sample sizes ranging from 17 to 514 patients. Despite being labelled as the highest level of evidence (Level 1 and Level II evidence), these studies had low Cochrane reporting quality scores among individual methodological safeguards. The Cochrane reporting quality scores did not differ significantly between Level I and Level II studies. Correlations varied from 0.0 to 0.2 across the 12 items of the Cochrane reporting quality assessment tool (p> 0.05). Among items closely corresponding to the Levels of Evidence Rating System criteria assessors achieved substantial agreement (ICC=0.80, 95%CI:0.60 to 0.90).

Conclusions: Our findings suggest that readers should not assume that

1) studies labelled as Level I have high reporting quality and

2) Level I studies have better reporting quality than Level II studies.

One should address methodological safeguards individually.

N. Maffulli G. Walley S. Bridgman D. Clement D. Griffiths G. Mackenzie

Introduction: Fifty thousand knee replacements are performed annually in the UK at an estimated cost of £150 million. However, there is uncertainty as to the best surgical approach to the knee joint for knee arthroplasty. We undertook a randomised controlled trial to compare a standard medial parapatellar arthrotomy with sub-vastus arthrotomy for patients undergoing primary total knee arthroplasty in terms of short and long term knee function.

Methods: Two-hundred and thirty-one patients undergoing primary total knee arthroplasty during 2001–2003 were recruited into the study. Patients were randomised into subvastus (116) or medial parapatellar (115) approaches to knee arthroplasty. The primary outcome measures were the American Knee Society and WOMAC Scores. The secondary outcome measures were patient based measures of EuroQol and SF-36. All outcomes were measured pre-operatively, 1, 6, 12 and 52 weeks post-operatively. We also looked at a pain diary, analgesia diary, ease of surgical exposure, and complications.

Results: Pain as measured by WOMAC was significantly less in the subvastus group but only at 52 weeks. The Knee Society Score showed some early benefit at one week to the subvastus group. There was no difference between the two groups in relation to the knee function score, EuroQol, SF-36, pain diary, analgesia usage and length of hospital stay

Conclusion: There is some benefit to patients receiving sub-vastus arthrotomy relative to medial para-patellar. Although the results show some statistical significance in using the sub-vastus approach the clinical importance of these findings and the costs of the various procedures involved remain to be ascertained.

R.W. Poolman P.A. Struijs R. Krips I.N. Sierevelt R.K. Marti F. Farrokhyar M. Zlowodzki M. Bhandari

Background: While surgical trials can rarely blind surgeons or patients, they can often blind outcome assessors. The aim of this systematic review was threefold:

1) to examine the reporting of outcome measures in orthopaedic trials,

2) to determine the feasibility of blinding in published orthopaedic trials and

3) to examine the association between the magnitude of treatment differences and methodological safeguards such as blinding.

Specifically, we focused on an association between blinding of outcome assessment and the size of the reported treatment effect; in other words: does blinding of outcome assessors matter?

Methods: We reviewed 32 identified RCTs published in the Journal of Bone and Joint Surgery (American Volume), in 2003 and 2004 for the appropriate use of outcome measures. These RCTs represented 3.4% (32/938) of all studies published during that time period. All RCTs were reviewed by two of us for:

1) the outcome measures used and

2) the use of a methodological safeguard: blinding.

We calculated the magnitude of treatment effect of blinded compared to un-blinded outcome assessors.

Results: The methodological validation and clinical usefulness of the clinician-based, patient-based, and generic outcome instruments varied. Ten of the 32 RCTs (31%) used a modified outcome instrument. Of these 10 trials, 4 (40%) failed to describe how the outcome instrument was modified. Nine (90%) of the 10 articles did not describe how their modified instrument was validated and retested. Sixteen (50%) of the 32 RCTs did not report blinding of outcome assessors where blinding would have been possible. Among those studies with continuous outcome measure, unblinded outcomes assessment was associated with significantly larger treatment effects (standardized mean difference 0.76 versus 0.25, p=0.01). Similarly, in those studies with dichotomous outcomes, unblinded outcomes assessments were associated with significantly greater treatment effects (Odds ratio 0.13 versus 0.42, unblinded versus blinded, p< 0.001). The ratio of odds ratios (unblinded to blinded) was 0.31 suggesting that unblinded outcomes assessment was associated with an exaggeration of the benefit of a treatment’s effectiveness in our cohort of studies.

Conclusion: Reported outcomes in RCTs are often modified and rarely validated. Half of the RCTs did not blind outcome assessors even though blinding of outcome assessors would have been feasible in each case. Treatment effects may be exaggerated if outcome assessors are unblinded. Emphasis should be placed on detailed reporting of outcome measures to facilitate generalization. Outcome assessors should be blinded where possible to prevent bias.

V.D. Shetty S.L. Vowler R.N. Villar

Introduction: There are a number of publications in the literature on managing post-operative pain and early rehabilitation after primary total hip replacement (THR). However, there has been very little work in the literature to study the influence of the anaesthetic technique used on the post-operative length of hospital stay following primary THR. We, therefore, wished to particularly study the influence of anaesthetic technique and the anaesthetist concerned on the length of hospital stay, as well as the effect of age and body mass index (BMI).

Methods: We studied 121 consecutive THRs in 109 patients. All procedures in our study were performed by the same surgeon using the same posterolateral approach, the same prosthetic design and the same physiotherapy protocol for all patients. Patients received either general anaesthesia alone (50 THRs) or a combination of general and local anaesthesia (lumbar plexus block; 71 THRs) from three separate anaesthetists. The mean age at the time of operation was 66.5 years (33 to 88). The influence of anaesthetist, anaesthetic technique, age of the patient and BMI on length of stay after primary THR was assessed separately.

Results: Our analysis showed that the length of hospital stay was greatly influenced by the anaesthetic technique used, those patients who received a lumbar plexus block having a shorter median length of hospital stay (3 days) than those who received general anaesthesia alone (5 days; p < 0.0001). The age of the patient was also critical (p = 0.003) as was the anaesthetist concerned (p = 0.01). BMI was unimportant.

Conclusions: For those surgeons who believe that a reduction in the length of hospital stay after primary THR is a worthwhile objective, we have one over-riding observation–the anaesthetic technique used is critical.

N. Maffulli S. Bridgman P. Richards G. Walley D. Clement G. MacKenzie Y. Al-tawarah D. Griffiths

Statement of Purpose: We tested the null hypothesis of no significant difference in arthroscopy rates for patients on a waiting list for arthroscopy in patients in which surgeons had a knee magnetic resonance imaging scan report prior to surgery, compared to those who did not have a report.

Methods and Results: This is a single-centre randomised controlled trial. 252 eligible patients consented and randomised. The two groups were similar with respect to a range of baseline factors. Very few arthroscopies were not performed–4.8% in the intervention arm and 5.5% in the control arm (χ2=0.06, df=1, p> 0.05). A longitudinal analysis of the secondary outcomes showed that there were no significant differences between the intervention and the control arms of the study.

Conclusion: Magnetic resonance imaging, prior to knee arthroscopy, does not lead to a reduction in the number of arthroscopies undertaken in the intervention group nor improve patient outcome in a range of secondary measures.

P.K. Schraeder U. Grouven R. Bender

Aim of the study: To calculate minimum-provider-volumes in total knee replacement by means of German routine data for the first time.

Materials and methods: In patients with primary total knee replacement (TKR) the correlation between hospital volume per year and risk of “insufficient mobility” (primary quality indicator) and “wound infection” (secondary quality indicator) was calculated by means of logistic regression models based on the data of 110.349 primary total knee replacements operated in 1.016 German hospitals in 2004.

Results: For both indicators a statistically significant relationship between hospital volume and outcome could be proven. Other risk factors such as age and ASA-status also had a significant influence, but did not appear as important confounders. The risk for the secondary quality indicator “infection” decreased constantly by increasing hospital volume, thus the curve was very flat. This supports the hypothesis that high volume hospitals show up to have a higher quality level than low-volume hospitals. A threshold value of 116 TKR per year (95% CI 90–141) could be calculated. However, the explanation value of the hospital volume was too low to derive a threshold level that clearly discriminates between good and bad quality of care. The relationship between the primary quality indicator “insufficient mobility” and the hospital volume unexpectedly showed a U-shaped distribution. This questions the concept of a minimum provider volume regulation for primary total knee replacement regarding the risk factor “insufficient mobility”. Therefore, in this case no quantitative threshold values were calculated.

Conclusion: This analysis supports the hypothesis of a volume-outcome-relationship in primary total knee replacement. However, a minimum provider volume that clearly discriminates between good and bad quality of care could not be calculated on basis of German quality assurance data.

N. Rosencher F.J. Singelyn C.C. Verheyen F. Piovella H.K. Van Aken

Continuous neuraxial or deep peripheral nerve blockade used to provide postoperative analgesia after major orthopaedic surgery is associated with a risk of spinal or perineural haematoma, especially in patients concomitantly receiving anticoagulants. Limited data on the use of fondaparinux in surgical patients in whom this procedure is performed are available. The EXPERT trial was an observational international study in patients undergoing major orthopaedic surgery designed to evaluate the overall efficacy and safety of once-daily 2.5 mg fondaparinux initiated 6 to 12 hours post-operatively and administered for 4±1 weeks after surgery. A 48-hour “therapeutic window” was applied in patients in whom a neuraxial/deep peripheral indwelling catheter was placed: one of the planned doses of fondaparinux was omitted, the catheter was removed 36 hours after the previous fondaparinux dose, and the next fondaparinux dose administered 12 hours after catheter removal. The primary endpoints were symptomatic venous thromboembolism (VTE) and major bleeding 5±1 weeks after surgery. These events were validated by an independent adjudication committee. Overall, 5704 patients (mean age ± SD: 66 ± 12 years) were recruited between July 2003 and October 2004. They underwent surgery for total hip replacement (52%, n=2941), knee replacement (40%, n=2263), hip fracture (6%, n=353), or other indications (3%, n=148). Fondaparinux was given for a median of 35 (range: 1–105) days. Many operations (62%) were performed under regional anaesthesia only. A neuraxial or deep peripheral nerve block catheter was placed in 29% (n=1630) of patients. It was removed between one and two days after surgery in 43% (706/1626), and between three and six days after surgery in 57% (920/1626). Overall, the rate of symptomatic VTE was 1.0% (54/5387); it was 0.8% (13/1535) in patients with catheter and 1.1% (41/3852) in patients without catheter, giving an odds ratio of 0.79 (95% CI: 0.42 to 1.49) in favour of patients with a catheter. The upper limit of the 95% CI being below the predetermined non-inferiority margin of 1.75, the efficacy of fondaparinux in patients with a catheter was therefore not inferior to that observed in patients without a catheter. The rate of major bleeding was 0.8% (42/5382) overall, 0.5% (7/1532) in patients with catheter and 0.9% (35/3850) in patients without catheter. No spinal or perineural hematomas or nerve damage were reported. At 5±1 weeks, 23 (0.4%) patients had died. In conclusion, 2.5 mg fondaparinux given daily for 4±1 weeks after major orthopaedic surgery was both effective and safe in routine practice. This benefit-risk ratio was similar in 1630 patients with a neuraxial/ deep peripheral indwelling catheter in whom a 48-hour “therapeutic window” was applied.

G.J. Rainey S. Khan I. Brenkel

Loss of blood is inevitable during knee replacement surgery, sometimes requiring transfusion. Allogenic blood leads to a risk of disease transmission and immunological reaction. There are various practices used. There is still a risk of bacterial transmission with stored blood and haemolytic transfusion reactions can still occur. Data was collected between 1998 and 2006. There was data on transfusion in 1532 patients undergoing primary knee replacements. There were 1375 unilateral TKRs and 157 bilateral TKRs. After reducing the bilateral cases to one record per patient, it was agreed to restrict the main analysis to 1532 patients. Data was collected prospectively at a pre-admission clinic 3 weeks prior to surgery. Haemoglobin was checked and body demographics including BMI were obtained. Each patient also had a knee score assessed. All patients received a LMWH pre-op until discharge. A tourniquet was used in each case and all patients had a medial para-patellar approach. No drains were used and operation details such as a lateral release were recorded. As per unit protocol, patients with a post-op haemoglobin less than 8.5g/dl were transfused as were symptomatic patients with haemoglobin between 8.5g/dl and 10g/dl. Each of the possible predictive factors was tested for significant association with transfusion using chi-squared or t-tests as appropriate. Multiple logistic regression was used to test for the independent predictive of factors after adjusting for one another. Results show that transfusion was more likely if the patient was older, female, short, light or thin. Among peri-operative factors, the chance of a transfusion was increased for bilateral patients, those with low knee scores and those with high ASA scores. Also patients undergoing a lateral release, those with low pre-op haemoglobin and those with a large post-op drop were more likely to be transfused. All the significant variables were entered into a forward stepwise multiple logistic regression. Transfusion was significantly more likely in those undergoing a bilateral procedure, with a low BMI, low pre-op haemoglobin and those with a large post-op drop (> 3g/dl). Allogenic transfusion is associated with immune-related reactions, from pyrexia to urticaria to haemolytic transfusion reactions, which can be life threatening. There is also the risk of viral pathogen transmission. Women were shown to be almost twice as likely to need transfusion. This has been shown in previous studies and is thought to be due to women having a lower weight and pre-op haemoglobin, both of which were shown to be significant independent factors in increasing the risk of transfusion. A pre-operative haemoglobin of less than 13g/dl, a BMI less than 25, and undergoing a bilateral procedure were shown to have an increased risk of transfusion. For patients falling into these categories, measures can be planned to try and reduce this risk.

Z.A. Matejovsky Z. Matejovsky I. Kofránek Z. Krystlik

The authors offer their personal experience with long term results on 71 patients (72 allografts) operated between 1961 and 1990. 23 were large osteoarticular grafts, 28 intercalary grafts and 20 fibular grafts. We used one composite hip endoprosthesis in 1988 after 16cm proximal femur resection due to Ewing sarcoma in a 10 year old girl. From the 23 osteoarticular grafts 14 (60%) are long term survivals including one after fracture salvage. Six had to be removed due to infection. From the 28 intercalary grafts 16 (57%) are surviving over 15 years. Infection occurred in 6 patients with chemotherapy. Two of them had intra-arterial CDDP and one additional radiation. All of the proximal humerus allograft had complete resorption of the proximal head within 3 years. The diaphyseal reconstructions with additional cancellous autografts incorporated within 3 years. The patient with the composite stem had two cup revisions, but the stem is doing well and we observed only a mild osteolysis at the proximal part of the graft between the 2nd and 5th year that remains stable. Fractures of the graft can be salvaged in most cases.

Infection leads to the removal of the graft in almost all cases. Factors influencing the survival, remodeling and complications of the grafts are discussed. The regime of cryopreservation, fixation and loading of the graft influence these factors together with the use of autologous bone chips around the allograft-host junction as well as the application of chemotherapy or radiation. Fracture of the graft can be salvaged in most cases in contrary to infection that remains the most severe complication that can occur at any time period. Even with the improvement of tumor endoprostheses the use of allografts remains an optional solution especially in young patients.

M.C. Kokkinakis K. Kafchitsas A. Rajeev J. Mortier M. Engelhardt

The osteochondral defect in the knee and ankle joint is a difficult and common problem in young population. The bone-cartilage autologous grafting represents a recently introduced treatment option for osteochondral lesions of the weight bearing articular surfaces of femoral condyles and talus.

The aim of our study was to evaluate the MRI findings, and in particular to find out about the fate and the time needed for the graft incorporation, to assess the continuity, homogeneity and smoothness of the cartilage layer of the transplant compare to the remaining cartilage, to estimate the viability of the graft and to determine the correlation between the MRI findings and the functional outcome.

We performed a prospective study and followed up 33 patients, who underwent osteochondral autografting for defects in both medial and lateral femoral condyles as well as in the talus. The grafts were harvested from the anterolateral region of the ipsilateral knee using an insider rinsing diamond bone-cutting instrument (DBCS). The grafts were implanted using press fit technique.

16(48%) women and 17 men were included in our followup with an average age of 38.4 years (age range-16to58 yrs). There were 20(60%) osteochondral defects in the femoral condyles and 13 in the talus. 13(40%) patients gave a history of trauma. All the patients were followed up with MRI scans between 1 to 4 years postoperatively.

The MRI study illustrated a cartilage contour interruption by 16(48%) patients and 19(58%) had uneven joint surface. 9(27%) of the patients were shown to have homogeneity between the graft and the surrounding bone and cartilage tissues. A subchondral oedema was observed in 2(6%) of the cases. Only 1 patient had a subchondral bone-oedema in the graft-donor site. All the autologous grafts were incorporated by 4 years as proven by MRI scans

The MRI evaluation revealed regular incorporation of the osseous part of the graft in the subchondral bone. On the contrary, cartilage layer integration was less common. The MRI findings did not show any correlation to the clinical outcome. Hangody (2003) reports all grafts to incorporate into the recipient bed and most articular surfaces to have congruency and similar appearance to the surrounding articular cartilage and bone in 6 years.

Despite using very accurate harvested autologous osteochondral cylinders, which fit exactly the defects, match precisely the corresponding chondral and osseous layers and cause no immune reactions, it was shown in this short term MRI followup that the height and the shape of the original articular surface cannot be fully restored. However the relief of symptoms and improved functional outcome are promising findings and define bone cartilage autografting as a currently efficient treatment of osteochondral lesions of knee and talus.

L.A. Aponte-Tinao G. Farfalli B. Politi E. Abalo M. Ayerza D. Muscolo

Introduction: Osteoarticular allograft represents a reliable option for distal femur reconstruction. The purpose of this study was to describe the technical details and results of distal femur tumor resection and reconstruction with an osteoarticular allograft.

Material and Methods: One hundred and twenty-two patients who received an osteoarticular allograft after distal femur resection were reviewed, with a mean follow-up of 7 years. Key points for successful fixation are allograft selection, absolute stability and satisfactory soft-tissue reconstruction at the time of surgery that allows aggressive rehabilitation. Survival of the allograft was estimated with the Kaplan-Meier method. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

Results: Three patients were lost to follow and twenty-three patients died for tumor related reasons without allograft failure. In the remaining 96 allografts, eighteen allografts failed due to 7 infections, 7 local recurrences, 1 massive resorption and 3 fractures. Overall allograft survival was 82% +/− 7.6% (+/− 2 SE) at five and ten years. Those patients who preserved the original allograft had an average functional score of 27 points and a mean radiographic score of 89%, which represents a good and excellent functional and radiographic result.

Discussion and conclusion: Osteoarticular allograft is a successful procedure for reconstruction of the distal femur. Adequate preoperative planning, careful surgical technique and aggressive rehabilitation lead to excellent function and low complication rate.

M.A. Ayerza G. Farfalli E. Abalo L. Aponte-Tinao D.L. Muscolo

Introduction: Unicompartmental osteoarticular defects of the knee are challenging due to demands of stability and function of this weight-bearing joint. Prostheses reconstruction often requires sacrificing the uninvolved compartment. Osteoarticular allograft reconstruction can restore the anatomy, and allows reattaching soft tissue structures such as meniscus and ligaments from the host. The purpose of this study was to perform a survival analysis of unicompartimental osteoarticular allografts of the knee and evaluate their complications.

Material and Methods: Forty unicompartmental osteo-articular allograft of the knee performed in 38 patients during the period 1962–2001, were followed for a mean of 11 years. In 36 patients, the bone defect was created by the resection of a tumor (33 giant cell tumors, 1 osteogenic sarcoma, 1 chondrosarcoma and 1 malignant fibrous histiocytoma) and in the remaining two by an open fracture. Twenty nine transplants were located at the femur that includes 11 medial and 18 lateral condyles. Eleven transplants were located at the tibia, including 4 medial and 7 lateral tibial plateaus. According to the reconstructed compartment, host meniscus and ligaments were reattached to the graft. Rigid internal fixation with plates and screws were used in each patient. Allografts survival from the date of implantation to the date of revision or the time of the latest follow-up was determined with the use of the Kaplan-Meier method. Complications as local recurrence, fracture, articular collapse and infection were analyzed.

Results: The global rate of allograft survival was 85% at five years. There were 8 complications in 6 patients: 2 local recurrences, 2 infections, 1 fracture, 1 massive resorption and 2 articular collapses. In 6 patients the allograft was removed and they were considered as failures. All these patients required a second allograft that included 2 unicompartmental and 4 bicompartimental reconstructions. The two patients with articular collapses required a regular total knee resurfacing prosthesis.

Discussion: Although the incidence of reoperations due to allograft complications may be high, the allograft survivor rate at five years was 85%. Unicondylar allografts, appear to be an alternative in those situations in which the massive osteoarticular bone loss to be reconstructed, is limited to one knee compartment.

M. Jakob W. Dick M. Heberer I. Martin

A major challenge to be faced in order to introduce cell-based therapies for bone repair into wide-spread surgical practice is to translate a research-scale production model into a manufacturing design that is reproducible, clinically effective, and economically viable. One possible means by which to achieve this goal is via a bioreactor system capable of controlling, automating, and streamlining all of the individual phases of the bone-tissue engineering process. In a first step to meeting this challenge, in this work we aimed at developing and validating a closed bioreactor system for

the efficient seeding of cells into 3-dimensional scaffolds and

the generation of osteoinductive constructs starting from human bone marrow-derived cells.

Our patented bioreactor technology essentially consists of scaffolds arranged in a circular plate, which is moved in alternating directions by a linear drive unit through a cell suspension/culture medium, thus resulting in the perfusion of the cell suspension/culture medium directly through the pores of the scaffolds in alternate directions. The cultivation chamber is fully isolated from the external environment, with liquid/gas exchange achieved through aseptic interfaces.

Human bone marrow nucleated cells from 3 donors were perfused through porous ceramic discs (8 mm diameter, 4 mm thick), resulting in adhesion of the osteoprogenitor cell fraction in the ceramic scaffolds. Efficiency of cell seeding was consistently greater than 80%. Cell seeded constructs were further cultivated under perfusion for a total of 20 days, resulting in the expansion of the osteoprogenitor cells directly within the scaffold pores and maintenance of greater than 90% cell viability. Ectopic implantation of the cultivated constructs yielded abundant and reproducible formation of bone tissue, distributed throughout the scaffold pores.

The developed bioreactor provides a simple and efficient approach

to establish and maintain 3D cultures of cells into scaffolds under perfusion, and

to generate osteoinductive grafts starting from minimally processed bone marrow aspirates and bypassing typical cell expansion in monolayers.

Incorporating the bioreactor unit into a system for automated medium change and monitoring/control of culture parameters is likely to lead to the development of a closed system for the standardized production of autologous cell-based bone substitutes.

S.A. Khan

Introduction: Extent of fibular resection dramatically alters limb function. Aim of our study was to evaluate the functional outcome following resections for 23 malignant tumors of fibula.

Methods: 23 biopsy proven malignant tumors of fibula were included in the study. There were 11 cases of Ewings sarcoma (PNET), 8 osteosarcomas, 2 malignant fibrous histiocytoma and 1 each of synovial sarcoma and chondrosarcoma. Following chemotherapy (wherever indicated) limb salvage surgery was done in all cases. There were 9 proximal, 6 middle and 9 cases of distal third of fibula. Type I resection was done in all proximal and 4 tumors of middle third fibula. Type II fibular resection with reconstruction of ankle joint was done in 10 cases. Reversal of contralateral fibula to reconstruct the ankle was done in 7 cases. Allograft was used in 3 patients.

Results: Average follow up was for 4.5 years (2 to 7 years). 17 patients (68%) were alive after 4 years of surgery. Local recurrence was seen in 3 cases and these were treated by above knee amputation. 3 patients died within 1 year of surgery. 82% of survivors had a good to excellent functional outcome according to the MSTS functional evaluation criteria and 65% were able to bear full weight and had unlimited activity. Recurrence was commonest in patients with PNET. All patients undergoing reversed fibular grafting showed good functional outcome.

Discussion and Conclusion: Results of limb salvage in malignant fibular lesions is infrequently reported. Site of fibular lesion is critical in salvage surgery and need for further reconstruction. Good results are obtained with reversed contralateral fibular reconstruction of the ankle.

E. Abalo G. Farfalli B. Politi L. Aponte-Tinao M. Ayerza D.L. Muscolo

Pupose: The purpose of this study was to analyze the outcome of proximal tibia osteoarticular allografts after tumor resections.

Material amd Methods: We performed a retrospective study over 58 patients in which a proximal tibia allograft reconstruction was undertaken. All patients were followed for a minimum of 5 years and allografts survival from the date of implantation to the date of revision or the time of the latest follow-up was determined with the use of the Kaplan-Meier method. In all patients, the patellar tendon from the host was reattached by suturing to overlapped donor flaps. Patients were clinically evaluated with the MSTS score system.

Results: The global rate of allograft survival was 65% +/− 12% (+/− 2 SE) at five and ten years, with no significant difference between patients who received chemotherapy and those who did not. Allografts needed to be removed in twenty patients due to 12 infection, 4 local recurrences and 4 fractures. Active knee extension was restored in all patients with an average functional score of 26.3 points.

Discussion: Survival analysis showed that 65% of proximal tibia osteoarticular allograft reconstructions remain stable at five and ten years. Patellar tendon reconstruction with allogeneic tissue in proximal tibia allograft restores active knee extension with an excellent functional result. Despite the incidence of complications, proximal tibia osteoarticular allografts continue to be a very valuable reconstructive procedure for large defects after resection of bone tumors.

G. Lob V. Heppert R. Laun T. Lob L. Rabenseifner

Introduction: Improved treatment of primary tumors leads to an increased life expectancy and thus to an increasing number of patients with bone metastases. Techniques like auto- or allogenic bone grafts, vascularised bone transfer and distraction osteogenesis often require multistage surgical procedures and inhibit full early limb function. Diaphyseal replacement using nails, plates and bone cement do not guarantee long term bone stability. Due to this experiences a new diaphyseal replacement device for humerus, femur and tibia has been developed.

Materials and Methods: The diaphyseal replacement implant OSTEOBRIDGE consists of two semi-circular cylindrical shells. The spacer is clamped around two nails via eight screws. Different sizes of spacers and nails can be used to bridge the bone loss correctly.

The outer diameter of the spacer ranges from 20–25–30 mm and the length from 40 to 70 mm. Two or three spacers can be combined via a special connector. Nails in the length 60 to 200 mm and the Ø 7 to 18 mm with the possibility of static or dynamic interlocking complete the modular system entirely made from Ti-6Al-4V.

Biomechanical Testing: Static compression tests to determine the maximum longitudinal forces of the clamp connection spacer/nail were performed, 4-point bending tests with the complete system to investigate the fatigue resistance were undertaken and torsional test to evaluate the rotational stability.

Prospectiv clinical evaluation: In between 2004 and 2006 35 patients were treated with the OSTEO-BRIDGE system.

The indication: Tumor: Humerus 8, Femur 16, Tibia 2, Postinfectious: Tibia 4, Posttramatic Femur 4, Tibia 2.


Biomechanical testing: the clamp connection spacer/ nail can neutralize axial loads which can not be expected in human beings. The clamp connection spacer/nail Ø 10 mm resisted an average axial load of 8,5 kN. This can be compared to a force of 850 kN (equivalent to 10 multiples of 85 kg body weight). The bending test with a nail Ø 10 mm shows that the spacer can resist long term loads from an occurring stress of 400 N/mm2 in the nail.

Clinical evaluation: All spacers are still in place and all are full functioning, except 2; one spacer in the femur had to be replaced by a second spacer due to bone cement incorporated during first operation.

One spacer was removed during amputation for recurrency of osteosarcoma. No infection, no loosing were reported.

Discussion: The OSTEOBRIDGE spacer system allows to replace lost daiphyseal bone over long distances with proved biomechanical stability. An advantage seems to be the early bony bridging over the spacer within the first 9 months. There might be another advantage in using the spacer as a container for antitumor, bactericidal or bone growth stimulating drugs.

D.A. Campanacci G. Scoccianti M. Mugnaini G. Beltrami L. Ciampalini P. De Biase R. Capanna

Ankle arthrodesis is considered a valid reconstructive option after bone tumor resection of the distal tibia, distal fibula and of the talus. The purpose of the present study was the review of author’s experience in ankle arthrodesis for bone tumors with the employ of bone grafts.

Over the last 15 years, 17 ankle arthrodesis were performed in author’s Institution for oncological pathologies. Average age at the time of surgery was 41 years (4–75). Twelve patients had a malignant tumor (3 osteosarcoma, 2 fibrosarcomas, 1 Ewing sarcoma, 1 emangioendotelioma, 1 condrosarcoma, 1 pleomorphic sarcoma, 1 adamantinoma and 2 metastases from renal carcinoma) and 5 patients had a benign tumor (4 giant cell tumors, 1 condroblastoma). In 13 cases the tumor involved the distal tibia, in 2 cases the distal fibula and in 2 cases the talus. In 15 patients we performed a tibiotalar arthrodesis and in 2 patients (tumors of the talus) a tibiocalcaneal arthrodesis.

The bone defect after resection was reconstructed with: cortical structural autografts from controlateral tibia and autologous bone chips from iliac crest in 5 patients; cortical structural autografts from controlateral tibia + cortical structural allografts + autologous bone chips from iliac crest in 2 patients; cortical structural allografts + autologous bone chips from iliac crest in 2 patients; structural autografts in 4 patients; autogenous vascolarized fibula in 4 patient with cortical allograft in 3 cases and autograft in 1 case. Stabilization was obtained by intramedullary anterograde nailing in 8 patients, plate in 2, two or multiple screws in 7 (including two tibiocalcaneal arthrodesis).

Three patients died before this review (1, 1.5, 7 years after surgery: 1 Ewing sarcoma, 2 patients with metastases from kidney cancer). Follow-up for alive patients ranged from 14 to 146 months (average 53). Two local recurrences were observed, in a Ewing sarcoma in 1 case and in a giant cell tumor in 1 case. One patient is alive with lung metastases but no signs of local recurrence. In all patients but one the arthrodesis healed successfully. In one case a deep infection occurred (with wound dehiscence) and the arthrodesis did not heal. Complications included 1 deep infection, 1 superficial infection of the donor site (controlateral leg) and 1 fracture of the controlateral tibia (donor site of cortical autograft) treated with plaster cast. Three patients underwent a secondary surgical procedure: two partial hardware removals and one myocutaneous sural flap.

The low rate of local recurrence (1/5 in benign tumors and 1/12 in malignant tumors) and the high percentage of bone union (16 out of 17) together with the satisfactory functional outcome showed that ankle arthrodesis with bone grafts can be an oncologically safe and a meccanically successful procedure in bone tumor surgery.

I. van der Geest M. de Valk H. Schreuder R. Veth

Introduction: Both enchondromas and chondrosarcomas are mesenchymal neoplasms which originate from cartilage cells, and they occur mainly in the extremities. Both these tumours are resistant to chemotherapy and radiotherapy, and surgery is the only treatment option. In the last few years limb saving procedures have become the treatment of choice. Intra-operative cryosurgery has been introduced as a local adjuvant therapy for skeletal benign and low-grade malignant tumours. It is applied after curettage of the lesion to destroy any remaining tumour cells, and to enlarge the oncological margin of resection. Since the introduction of cryosurgery as an adjuvans, oncological and functional results of this extremity sparing surgery are significantly enhanced.

Patients and Methods: A retrospective study was conducted to evaluate the oncological and functional results, and the complications of cryosurgical treatment.

Data were prospectively collected from the tumour register and patient records. Functional scores of the affected limbs were assessed according to the Musculo-Skeletal Tumour Society scoring system.

Results: Between 1994 and 2003 123 patients (47 men, 76 women, average age 49 years; range 13–83 yrs) were treated with curettage and cryosurgery for an Enneking stage 3 enchondroma (75 patients) or a low-grade chondrosarcoma (55 patients).

The minimal follow up was two years, and the average follow up 50 months (range 24–119 months).

At follow up three recurrences had occurred in patients treated for enchondroma. One residual tumour was diagnosed in a patient with chondrosarcoma grade Ib. All patients were treated again with curettage and cryosurgery and disease free at the latest follow-up.

Of the 37 complications the most common were a fracture at the surgical site (18), fracture of osteosynthesis (6), 3 wound infection (3), delayed soft tissue healing (3), and transient nerve palsy (3).

Functional MSTS scores increased in time to an average of 28 points (94%) at two year follow up. No significant difference in scores were found regarding to localisation of the lesion, age or gender. A significant discrepancy in functional scores was observed between patients who did suffer from one or more complications and patients who did not.

Conclusion: We believe that the use of cryosurgery is an excellent adjuvant therapy after curettage to achieve local control of aggressive enchondromas and low grade chondrosarcomas. It avoids the need for segmental resection, making reconstruction of the bony defect easier and therefore results in excellent functional outcome. Due to the initial high fracture rate osteosynthesis at the surgical site is used more often, and weight baring mobilisation is postponed until full consolidation is reached.

A. Krueger M. Tannast S. Kohl M. Beck K. Siebenrock

Introduction: In the treatment of polytraumatised patients acetabular fractures are challenging because of the necessity of perfect open reduction of the articular surface over an anatomy respecting approach. Luxation of the femoral head with accompanying Pikin fracture, interponated fragments and labral lesions are relevant additional injuries compromising a good result after correct operative treatment. The choice of the approach is a limiting factor for the visualization of the hip joint and is of capital importance for adequate internal fixation. A modified Kocher-Langenbeck- approach with osteotomy of the grater trochanter allows an anatomic reduction under perfect visualization with protection of the soft tissue.

Patients and Methods: This prospective study was accomplished from 1995–2003 including 60 patients (16 female, 16–80years) with an actabulary fracture (posterior wall-, T-type-, and transverse fracture) treated over a modified Kocher-Langenbeck-appraoch with osteotomy of the grater tro-chanter. The included patients had a minimum follow-up of 2 years with clinical and radiological examination. The outcome was assessed with the Merle d’Aubigné-score and degenerative changes with the Tönnis classification.

Results: Within 57 patients an anatomic reduction was achieved. In 3 patients the reduction was not anatomical but satisfactory (1–3mm). Arthrotic changes in the minimujm follow-up of 2 years were observed in 14 patients (8 Ps grade I, 3 Ps grade II, 3 Ps grade III). In 3 patients posttraumatic arthritis had to be treated with THR (1, 3, 8 years postoperatively). A avascular necrosis was not objected.

Conclusion: The treatment of suitable acetabular fractures over a modified Kocher-Langenbeck-approach with a osteotomy of the greater trochanter and dislocation of the femoral head is a safe method for anatomic reduction and internal fixation

K.å. Jansson P. Svedmark E. Buskens M. Larsson P. Blomqvist J. Adami

Introduction: Spinal fractures are associated with pain, disability, neurological dysfunction and mortality. Osteoporosis and risky leisure time activities are increasing in the population. New treatment options have been introduced. However, only a few international studies have reported its descriptive epidemiology. There are no clear consensuses regarding the choice of operative interventions versus non-operative treatment in patients with thoracolumbar fractures. Treatment is often based on local traditions, skills and experiences. The aim of this nationwide study is to analyse the incidence, the characteristics of the patients, the subsequent development, surgical incidence and mortality rate among hospitalized patients with thoracolumbar fractures in Sweden.

Methods: All discharges between 1997 and 2000 with diagnoses of thoracic or lumbar vertebrae fracture according to ICD 10 classification were selected from the National Inpatient Register. Surgery in these patients was categorised by procedure codes indicating spine operations. In order to calculate the risk of patients dying, linkage was performed to the Swedish Death Register using the unique personal identification number.

Results: We identified 13, 496 admissions during the study period. This corresponds to an incidence rate of 30 per 100, 000 person-years and the occurrence was stable during 1997 and 2001 for patients younger than 50 years but decreased for patients above 50 years. The incidence of spine surgery among all patients was 1.9 per 100, 000 person-years, ranging from 1.6 per 100, 000 inhabitants per year to 2.6 per 100, 000 in the different region of Sweden. The most common causes of the fracture were falls (53 %) followed by vehicle accidents (37%). Almost two thirds of the patients operated on were men (63 %) and two thirds had lumbar vertebral fractures (66 %). The median age of the patients operated on was 42 years. The median length of stay was eight days. Among those who was operated the 30 days case fatality rate was 0.7 %. Median age for death was 64 years. Operations were less common in women (OR 0.79). The number of patients operated on during the last study year 2001 was significantly increased (OR 1.29). The probability of being operated on was highest in the more urban and densely populated regions of Stockholm and southern Sweden.

Discussion: This national study based study showed a stable cumulative incidence of thoracolumbar fractures over the year 1997–2000. However, the two last year of this study an increased incidence of operation was observed. A possible explanation of this finding could be the new percutaneus technique for verterbroplasty. We find it of most importance to further investigate the reasons behind the gender differences in surgical incidence in patients with vertebral fractures


The authors present their experience of acetabular fractures, as examined according to Harris’ recent (2004) CT based classification into four separate groups and relative sub-groups.

Each group is here represented as a completely documented clinical case, with pre and post-op roent-grams as well as axial and volume rendering CT imagery.

The Harris classification differs from the classic and 40 year old Letournel classification, basically ignoring the fracture complexity and focusing on the pattern of the fracture itself, with respect to column walls and extension beyond the acetabulum. It’s also possible to include some commonly seen fractures otherwise not classified by Letournel. Fracture comminution therefore is not a defining characteristic.

This topographic approach is easier for the surgeon to comprehend and memorize, thus facilitating pre-operative planning and the possibility of interdepartmental assessment of the fracture types.

Obviously, computerized tomography is the defining technique of this classification. The axial CT display of acetabular fracture patterns within the pelvis is furthermore confirmed by the 3D reformatted images.

This classification is loosely based on that of Tile and Helfet ; with the advantage of further simplifying the sub-groups from 27 to 16.

The Harris classification is simple and unambiguous, providing clear indications for both diagnosis and surgical treatment planning of this most complex chapter of Traumatology.

J. Mutimer M. Ockendon T. Chesser W. Anthony

Introduction: Posterior wall acetabular fractures are potentially difficult fractures to treat due to difficulties associated with the types of approach, reduction and fixation required. Spring plates are a method of maintaining such fractures reduced.

Aims: To assess the clinical and radiological outcome with spring plate fixation of posterior wall fractures.

Materials and Methods: From July 1993 to August 2004, 91 patients with 92 displaced posterior wall fractures underwent posterior wall fixation with one or more spring plates.

All patients were assessed postoperatively with a CT scan and annually for up to 5 years for a clinical and radiological assessment. Clinically patients were graded according to the Epstein modification of Merle D’Aubigne/ Postel Hip Score. The radiographs were graded using the Roentographic Grade criteria used by Matta.

Results: Patients were reviewed at a mean 44 month follow up.

At the time of operation 40% of fractures were reduced anatomically. There were 12 post operative complications.

Clinically excellent or good results were seen in 70% and radiologically in 68%. There were 11 revisions for osteonecrosis, infection and osteoarthritis.

There was a high correlation between the accuracy of the reduction and the subsequent prognosis.

Conclusion: Posterior wall fractures can be treated successfully by the use of spring plates. Clinical results correspond closely with radiological appearance. The accuracy of reduction correlates highly with the subsequent prognosis and we recommend routine postoperative CT scanning to identify misplaced metalwork and the accuracy of reduction to help predict prognosis.

A. Pizzoli N. Rossi

Anatomical reduction of the joint is the primary aim in the treatment of acetabular fractures as any other articular fracture. The current standard approach provides open reduction and internal fixation (O.R.I.F.) through a variety of surgical approaches which have been associated with relatively high complications rate such as haematomas, deep infection, and neuro-vascular lesions. These procedures need long operative times with significant blood loss.

Many authors have demonstrated the feasibility of closed reduction and percutaneous fixation (C.R.P.F.) for minimally or non displaced acetabular fractures; this technique can be considered a valid alternative to O.RI. F. in order to decrease the morbidity related to surgical approaches.

Between 2001 and 2006 we performed C.R.P.F. for acetabular fractures in 15 patients; the reduction has been controlled with fluoroscopy during the operation and with CT scan after the operative procedure. The osteosinthesis has been performed with cannulated screws and In more complex cases the reduction has been achieved and maintained with ileo-femoral external fixation (ligamentotaxis technique).

Fractures were classified according to AO classification. Clinical and functional results have been evaluated according to Harris Hip Score on the base of post-operative CT scan and on x-ray films at last follow-up.

According to our experience the use of external fixation in the treatment of acetabular fractures must be reserved for very selected cases in which for general or local condition the joint the distraction associated with minimal internal fixation can guarantee good reduction and fracture stability avoiding the poor results of conservative treatment or the risk of major complications related to ORIF. The best reduction can be achieved when the treatment is carried out early while the best stability is achieved with the association of percutaneous cannulated screws. The use of external fixation has never compromised the range of movement of the hip.


Purpose: The authors would like to report the outcome following evaluation of surgical treatment for acetabular fractures with more than 10 years follow-up.

Materials and methods: 133 consecutive patients were evaluated with 10–16 years post surgery follow-up (mean 12 years). Mean age was 34 years (17 to 70 range) and male: female were 2:1. 90% of our cases were tertiary referrals. The follow-up assessments included AP pelvis and Judet view radiographs and clinical evaluation was performed with the Harris hip score, Modified Merle d’Aubigne score and the SF 36v2 health survey.

Results: Fracture reduction was anatomical in 69% of the patients and in 31% it was non-anatomical. The reduction of the acetabular fractures was considered anatomical when all five lines on post-operative radiographs were corrected and the hip was congruent. Among our patients, 19% had excellent clinical results according to the modified Merle d’Aubigne Score and 58% according to the Harris Hip Score. A poor clinical outcome was identified in 18% of our patients according to the modified Merle d’Aubigne Score and 23% according to the Harris Hip Score. Radiographic evidence of osteoarthritis was in 35,8% of our patients (all grades of arthritis). 6 of our patients had neurological complications (sciatic nerve palsy) (3 pre-operatively, 2 post- operatively and in one patient there was a delayed sciatic nerve palsy secondary to haematoma). In 7 patients (8.6%) there was heterotopic ossification but in only three that was clinically a problem. Two patients developed intraoperatively pulmonary embolism. We had no post-operative deep vein thrombosis or pulmonary embolism.

Conclusions: Our results compare favourably with those of previous published studies with shorter follow-up period. Anatomical fracture reduction is mandatory and improves the clinical outcome. Infection and avascular necrosis are associated with poor clinical outcome. Early surgical intervention for displaced acetabular fractures can improve the final outcome.

H.L. Soberg A. Finset E. Bautz-Holter L. Sandvik O. Roise

Background: The assessment of factors associated with return to work (RTW/NRTW) after multiple trauma is important in trauma research. Goals in rehabilitation should comprise RTW. The purpose of this study was to examine the RTW rate and which factors that predicted RTW for patients with severe multiple injuries using a prospective cohort design.

Methods: 100 patients with a New Injury Severity Score (NISS) > 15, age 18–67 admitted to a Level I trauma center were included starting January 2002 through June 2003. Outcomes were assessed 6 weeks after discharge, 1 and 2 years post-injury. Instruments were the Brief Approach/Avoidance Coping Questionnaire, Multi-dimensional Health Locus of Control, SF-36, the WHODAS II and the COG for cognitive functioning.

Results: Mean age was 34.5 years (SD 13.5), 83% were male. Mean NISS was 35.1 (SD 12.7). 66% were blue-collar workers. At 1 year 29% achieved complete RTW, 43% at 2 years. Mean time back to work was 12.8 months (SD 5.9). Differences between the RTW/ NRTW groups concerned personal and demographic variables, and physical and psychosocial functioning. Survival analysis showed that risk factors for NRTW were lower education, length of stay in hospital/rehabilitation > 20 weeks and low social functioning shortly after the return home.

Conclusions: The majority of the patients had not completely returned to work 2 years post-injury. Demographic and injury related factors and social functioning were significant predictors of RTW status.

A. Athanasopoulou V. Psychoyios G. Galani H. Dinopoulos O. Paisios

Aim: The aim of the study was to investigate the efficacy of the multidetector CT scan in the diagnosis and classification of pelvic and acetabular fractures.

Material and Method: 41 patients, 13 women and 28 men suspect for acetabular or pelvic fracture were examined. Patient’s ranged from 15 to 72 years. Fracture classification was based in that of Letournel and Judet. Examination was performed with a Multidetector CT scanner (Phillips-Brilliance), withnmultiple detectors and thin slices of 2 mm Multilevel and three dimensional reconstructions were performed.

Results: in 15 patients suspects for pelvic or acetabular fracture in plain xray, the CT scan was negative for revealing a fracture. In the rest 26 patients, there were 19 fractures of the anterior column, 4 fractures of the posterior column, 11 acetabular fractures and 7 sacral fractures. All the fractures were detected at the horizontal plane. MPR views were offered additional information for the sacral and acetabular fractures. In 7 patients the fractures diagnosed only after the CT scan was performed. In these patient plain x-rays were negative for fracture. In 6 patients the treatment algorithm was modified, based on CT scans findings

Conclusion: We believe that MDCT is an appropriate as well as an essential method in patients suspects for pelvic or acetabular injuries. MPR and three dimensional reconstructions are very helpful in revealing the personality of the fracture element very important for classification purposes as well as for planning treatment.

G.H. Kelalis K. Zahariou L. Kollintzas A. Kalampokis A. Morakis

PURPOSE: To record our experience in surgical treatment of thoracic spine fractures with posterior stabilization, decompression and ligamentotaxis.

MATERIALS AND METHODS: From January 2000 until July 2006, 67 patients (48 males and 19 females), aged 16 to 85 years old (average 41,2 y.o) were surgically treated in our department due to thoracic spine fractures. Preoperative X-Ray and CT scan were used in all cases while in most of the cases we performed MRI to further evaluate the damage. In all cases we performed decompression and posterior stabilization using four different hardware types and whenever possible ligamentotaxis. Continuous electrophysiological monitoring was alo ued in all operations. We recorded the pre- and postoperative neurological status, the vertebral height loss, the kyphotic angle and spinal canal occupation. Moreover we recorded the average hospitalization time, the transfusion needs as well as major and minor complications. At the follow-up we measured the loss of correction at 3, 6 and 12 months postoperatively. The follow up ranged from 4 to 48 months.

RESULTS: Neurological damage was recorded in 43 % of the patients. The average preoperative kyphotic angle was 38.2° while the average spinal canal occupation was 29.8 %. The immediate postoperative correction was 16.7 °. During the follow-up we observed small, insignificant loss of correction. There were no major complications.

CONCLUSION: In cases of thoracic spine fractures the surgical treatment with posterior stabilization and ligamentotaxis is offering significant stability and adequate long term results.

B. Anand A. Anand J. Sutcliffe M. Akmal

Injuries to the spinal cord are rarely isolated problems. Multiple trauma patients with spinal injuries can face significant long-term disability. In this retrospective, descriptive study we investigated the relationship between the level of spinal trauma and the injuries associated with this. We aimed to define the populations at risk and highlight trends identified.

METHODS: Analysis of 1500 trauma patients admitted to the Royal London Hospital by the Helicopter Emergency Medical Service (HEMS) over 6 years was undertaken. 265 patients of these patients had spinal cord injuries (SCI). Data was obtained from the HEMS trauma registry, patient records and interviews with patients.

RESULTS: 265 patients sustained SCI (mean age: 38 25% female). The most common mechanisms of injury were motor vehicle accidents (46%) and falls (29%) Attempted suicide was a common cause of SCI in our study group (mean age 32. M:F ratio 2:1) The most common associated injuries were limb and head trauma. C-spine injuries were the most common spinal injury and were associated with the highest mortality rates (37%). C-injuries presented with a bimodal age distribution, 84% had head trauma and 30% had significant chest injuries. In patients who sustained thoracic spinal injuries 71% had severe chest injuries and 34% had head injuries. The most common associated injury in lumbar spine trauma was injuries to the limbs or pelvis (68%). Injuries to the lumbar spine occurred more frequently in the 20–40 year old age groups.

Discussion: Mortality rate in our study was 26%. Mortality rates were highest in patients with cervical spine injuries (37%). The causes of mortality were from suicide attempts, falls and RTA. The mortality rates in these groups were 20%, 22% and 32% respectfully. Our review highlights significantly higher mortality in the over 60-age group. Our population had high numbers of suicide attempts. We highlight suicide attempts as a significant aetiology for SCI. All the deaths in the suicide group were as a result of jumping from high buildings. In patients over 60, c-spine injuries are by far the common level of SCI. Subdural haematomas occurred in almost 10% of patients with c- spine injuries. Any injury to the cervical spine should therefore prompt investigation for intracranial trauma. The GCS should be closely monitored and a low threshold for performing a CT scan is advisable. Thoracic spine injuries are strongly associated with severe chest injuries. Lumbar spine and sacral injuries are strongly associated with severe pelvic and lower limb injuries. Understanding the demographics and etiology is essential to allow effective planning for spinal services. Appreciating the injuries associated with SCI should ensure better care for patients, by recognizing problems earlier and using a multidisciplinary approach to optimize treatment and reduce morbidity and mortality.

K. Lunsjö A. Tadros A. Hauggaard R. Blomgren F. Abu-Zidan

Background: Whether pelvic fracture instability is correlated to mortality in blunt multi-trauma patients is debatable. This is the first prospective study on patients with pelvic fractures aiming at finding whether pelvic fracture type affects mortality.

Methods: 100 consecutive patients (77 males, mean age of 31 (3–73) years) were studied between September 2003 and October 2004. Data were collected regarding mechanism of injury, associated injuries, injury severity score (ISS), blood transfusions and mortality. The fractures were classified according to instability where type O is stable, type R rotationally unstable and type RV both rotationally and vertically unstable. Since a pure acetabular fracture is a single break in the pelvic ring, we classified it as type O. Computer tomography was used for fracture classification in 73 patients and plain X-rays in 27 patients.

Results: 77 fractures were caused by road traffic collisions. Type O fractures (n 63) had lower median ISS (13(4–48)) than type R (n 19) (18(9–75)) and type RV (n 18) (18(6–66)) (p=0.019, Kruskal Wallis). There was no significant in ISS between type R and RV fractures. A logistic regression model has shown that ISS was the only significant factor that predicts mortality.

Conclusion: ISS is the most importnt predictor in defining mortality in patients with pelvic fracture and not the type of pelvic instability.

B. Sokòlski A. Caban A. Zawadzki I. Francuz D. Szydłowski K. Wojnarski

The aim of the study: The authors are going to compare three treatment methods of ring pelvic fractures: operative, non-operative and with the use of an external fixator.

Material and methods: Between 1995 and 2005, 395 patients with pelvic ring fractures were treated at our department. 131 patients took part in this study. There were 84 (64,1%) males and 47 (35,9%) females. The common reason of the injury were car accidents 98 patients (74,8%), the second were falls 23 (17,5%), crush 7 (5,4%) and others 3 (2,3%). All patients were initially evaluated with use of three standard plain radiographs (anterioposterior radiograph, inlet and outlet projection according Penal & Tile) and computerized tomography scans and three-dimensional reconstructions of the scans. These studies were used to classify the fractures according to the classification of Young-Burgess. There were LC I 24, LC II 30, LC III 2, APC I 8, APC II 22, APC III 8, VS 10, CMI 27 fractures. 39 patients (29,8%) were treated no operatively, 48 patients (36,6%) were treated with use of the external fixator, 18 (13,7%) patients were treated by combination of open reduction and fixation with additional external fixation, and the rest of patients (26, 19,9%) were treated by open reduction and fixation.

Results: The clinical results were evaluated according to the Majeed scale. Long term clinical results were for individual type of fractures: LC I- 14 excellent, 6 good, 4 fair, 0 poor;

LC II- 11 excellent, 6 good, 8 fair, 5 poor; LC III- 0 excellent, 2 good, 0 fair, 0 poor;

APC I- 5 excellent, 2 good, 1 fair, 0 poor; APC II- 14 excellent, 5 good, 3 fair, 0 poor;

APC III- 3 excellent, 0 good, 4 fair, 1 poor; VS- 5 excellent, 2 good, 3 fair, 0 poor;

CMI- 9 excellent, 7 good, 7 satisfactory, 4 poor,

Conclusion: A comparison of the non-operative and operative methods showed that anatomical open reduction and fixation gave the shortest time of treatment and better clinical results. The anatomical reduction and fixation the posterior parts of the pelvic is the key to good long term clinical result of treatment.

A. Tötterman J.E. Madsen N.O. Skaga O. Röise

Objective: To assess the impact of EPP on physiological parameters in hemodynamically unstable patients with blunt pelvic trauma.

Methods: Of 661 patients treated for pelvic trauma, 18 consecutive patients in shock underwent EPP with the intent to control massive pelvic bleeding. These patients constituted the study population. Data collected from the medical records and the Ullev̊l Trauma Registry included: demographics, fracture classification, additional injuries, blood transfusions, surgical interventions, angiographic procedure, physiological parameters and outcome. An association between continuous variables was calculated using the Spearman correlation coefficient. A comparison between means was calculated using the t-test.

Results: Mean patient age was 44 years (range 16–80). ISS 47 (9–66). 39 % had non-measurable blood pressure at admission. Survival rate within 30 days was 72% (13/18) and correlated inversely to the age of the patient (p=0.038). Only one non-survivor died of exsanguination from multiple bleeding foci. A significant increase in systolic blood pressure (p=0.002) and hemoglobin count (p=0.012) was observed immediately after EPP. Arterial injury was observed in 80% of patients who underwent angiography after EPP.

Conclusions: 30-day survival rate after EPP was 72 %. A significant increase in systolic blood pressure and hemoglobin count was observed immediately after EPP, indicating that EPP as part of a multi-interventional resuscitation protocol may be life-saving in patients with exsanguinating pelvic injury. However, the high rate of arterial injuries seen after EPP indicates that the procedure should be supplemented with angiography once the patient is stabilized for transfer to the angiography suite.

A.Y. Milukov

From the appearing of the first works of R. Judet, E. Letournel, M. Tile up to this day, the methods of pelvic surgery changed cardinally. These operations are technically complicated and accompanied by blood loss. That’s why the low-invasive surgical methods including endoscopic approach are perspective.

The endoscopic methods of reposition and osteosynthesis offer advantages which are expressed in increasing of injury visualization, reduction of surgical incisions and fast postoperative restoration. A surgeon using the method of osteosynthesis needs endoscopic skills and thorough knowledge of standard surgical approaches.

We have the experience of the treatment of 12 patients. We consider that the indications for these operations are not only a type of pelvic injury, but also anatomico-technical moment: an opportunity of creating of workspace.

We have 2 techniques:

endoscopic osteosynthesis with using of pelvioscope;

optical endoscopic osteosynthesis.

In any case, it is necessary to create the workspace from a small incision above the injury region by the method of tissue pneumotization. Fracture reposition is realized using a fracture table and reducing attachments. Osteosynthesis is immediately carried out with both standard and original steel constructions using the special tools that we developed and produced (ports, drill, screwdrivers etc.). The intraoperative blood loss was not more than 150 ml in all cases and in the postoperative period in drains–not more than 100 ml. The promotion of the patients was realized by the standard methods. There were no complications. The good functional result was in all cases.

We think that further development of such techniques will allow to activate pelvic surgery on the new qualitative level.

A.Y. Milukov A.A. Pronskih V.V. Agadzhanyan

Materials and methods: We treated 415 patients with pelvic fractures. According to the classification of M. Tile, the fractures were allocated in the following manner: A-40%, B-31%, C-29%. 46% of these patients were admitted with different rates of severity of the shock state. Osteosynthesis was carried out in 51% cases: 27%- the external fixation only, 10%–internal constructions only and 14%–combined synthesis. The treatment of pelvic fractures must correspond to the requirements of anti-shock measures and to the treatment of intra-articular lesions. The most informative method of the radial diagnosis is CT examination with three-dimensional pelvic reconstruction. We oriented toward the severity of pelvic lesion (A, B, C) for the determination of the terms, the volume and the order of surgical interventions. We carried out the total volume of surgical interventions in the consideration of the severity of pelvic lesions in the shock of I and II rates. We used the internal or combined osteosynthesis in the partial or total loss of pelvic stability (B and C types). Internal osteosynthesis of the pelvis is biomechanically substantiated, because it regains the circular form, consequently, the pelvic stability too, it decreases the hemorrhage from the fractures regions, removes the pain more rapidly. Hemorrahage compensation was realized by intraoperative autohemotransfusion. In case of another dominant lesion, we operated by means of two brigades. In the shock of III and IV rates we carried out the pelvic stabilization only by the external fixation apparatus for the improvement of common state of the patient. The closed reposition and the osteosynthesis by external fixation apparatus with anterior frame do not ensure completely in the fractures of type C, but it is the most rapid method to obtain and to maintain of reposition in the future.

Results: Functional results were appreciated at the moment of discharge and after 12 months according to Majeed S.A. scale (1989) and according to data of computerized optic topography to appreciate the postural balance. Good and excellent results (70–100 points for the workers and 55–80 points for non-workers) were in 49% patients at the moment of discharge and in 82% patients after 12 months. Lethality value was 5,3%. Invalidism value was 6,9%. The mean terms of hospital stay were 32 days and the mean terms of resuscitation department stay were 1,5 days.


The treatment of the patients with severe injuries of pelvis in polytrauma must be realized in special clinics, with necessary equipment and specially prepared nursing.

Treatment tactics depends on the severity of common state and on the severity of pelvic injuries.

F.D. WADIA M.R. Smith M. Vrahas G. Velmahos H. Alam M. Demoya

Introduction: Patients with complex pelvic fractures with uncontrollable haemorrhage have a very mortality from pelvic haemorrhage and associated injuries. Management remains controversial and includes an number of techniques including pelvic stabilisation, angiography and direct surgical control of haemorrhage. Packing the pelvic cavity is a technique used rarely in this situation but is popular to control haemorrhage from other sources in similar situations. We have reviewed our experience of pelvic packing for uncontrollable haemorrhage to assess the effectiveness of this technique.

Materials & Methods: From a prospectively gathered database of 132 patients with significant pelvic fractures admitted between April 2002 and December 2005, 8 patients (5 males and 3 females) with an average age of 52.9 yrs were identified who underwent pelvic stabilisation and packing as an emergent life saving procedure for uncontrolled haemorrhage associated with pelvic fracture. Basic data including their presenting vital signs, pelvic fracture pattern and associated injuries were recorded. All were subject to pelvic stabilisation packing and their subsequent clinical course including their transfusion requirements and additional management was also assessed

Results: 6 out of these 8 patients died, 5 within the first 24 hrs after injury and one after 14 days from sepsis & MOF/MODS. The exact source of bleed could not be identified in any of these patients and was assumed to be venous and from large fractured bony surfaces. 4 patients had angiography and embolisation in addition and 2 of these survived.

Conclusion: The mortality of haemodynamically unstable pelvic fractures remains high and all modalities of treatment should be used to control bleeding. Pelvic packing may form an important part in the armamentarium of haemostatic measures; its role, however, needs to be better defined by larger multi-centre studies. Although difficult to conclude, the pelvic packing may have been responsible for reducing the mortality in this subgroup from a 100% to 75%.

W. Witzleb U. Hanisch J. Ziegler K. Guenther C. Rieker

Aim: The purpose of this study was to analyze the in-vivo wear rates of Birmingham Hip Resurfacing (BHR, Midland Medical Technologies Ltd., Birmingham, U.K.) explants and to contrast the results to the wear rates of conventional 28 mm metal-on-metal bearings (Metasul, Zimmer GmbH, Winterthur, Switzerland).

Methods: The wear rates, measured by a coordinate measuring machine (CMM5, SIP, Geneva, Switzerland), of 6 femoral components and two complete pairings of the BHR retrieved from 8 hips were contrasted to 43 28 mm heads from second generation metal-on-metal bearings (Metasul, Sulzer Orthopaedics Ltd., Winterthur, Switzerland).

Results: After 13 months (7 to 24) the BHR femoral heads showed a median volumetric wear rate of 2.9 mm3 (interquartile range: 0.8 to 7.1), slightly, but not significantly higher than the investigated 43 28mm Metasul heads (0.8 mm3/year, p = 0.067, 14 months [7 to 24] in-situ). One BHR case with a cup abduction angle of 70° showed a significant higher wear rate of 17.8 mm3. All BHR cases showed only small amounts of metallic particle histological and correspondingly, a mild histiocytic tissue response without foreign body granuloma formation.

Discussion: During the first two years after surgery the investigated BHR components showed wear rates substantially lower than conventional polyethylene bearings, comparable to Metasul bearings, implanted with very successful clinical results. But whether the wear rates will drop down after the so called running-in period comparable to conventional metal-on-metal bearings and provide young and active patients with a biologically acceptable particle volume over a long time period, still remains to be seen.

E. Kheir E. Tsiridis S. Mehta P. Giannoudis

Background: Acetabular or pelvic ring injuries are invariably associated with high-energy trauma that could lead to a significant degree of disability. The purpose of this study was to investigate whether patients who had surgical treatment of isolated acetabular or pelvic injuries were able to return to their previous sporting activities.

Patients and Methods: Between Jan 2001 to Jan 2002, 68 consecutive patients were treated in our institution with isolated pelvic (PF) or acetabular fractures (AF). Demographics, fracture classification, rehabilitation, outcome and complications were documented prospectively. Frequency, level of activity and sports participation before and after surgery, as well as EuroQol (EQ-5D) was also recorded.

Results: There were 58 male and 10 female patients, with a mean age of 42 years (16–80) and mean follow-up 30 months (24–36). 43 out of 53 (81%) patients in AF group and 13 out 15 patients in PF group (83%) returned to a variable level of sports activity. Significant reduction in the level of activity was observed in those who sustained both column (BC) (p< 0.04) and posterior wall (PW) (p< 0.0009) fractures in the AF group. Significant reduction in frequency of sports practice also found in PW subgroup (p< 0.0001). Patients < 25 and > 40 years of age in PF group and < 40 or > 65 in AF group had significant reduction in EQ-5D scores in comparison to normal UK population.

Conclusion: The majority of patients returned back to sports activities following surgery. The worst prognosis lies with BC and PW acetabular fractures. Middle age patients do better comparing to younger or elderly patients in both groups.

S. Glyn-Jones D.J. Beard D.W. Murray H.S. Gill

Introduction: Interest in hip resurfacing has recently been renewed by the introduction of metal-on-metal designs; it is being increasingly used for young patients, with over 30,000 implanted worldwide. The 5 year clinical results appear promising, but there are no long term data available. Radiostereometry (RSA) measures of implant migration have been able to predict implant failure; specifically large and continuous migration predicts aseptic loosening. We present the results of a five year RSA study examining the migration of the Birmingham Hip Resurfacing (BHR).

Methods: Twenty-four subjects with primary OA were implanted with the BHR device and with bone markers for RSA. RSA measurements were taken at 3, 6, 12, 24 and 60 months. The migration of the head and the tip of femoral component were measured in 3D.

Results: Preliminary analysis showed that the total 3D migration of the head and tip over five years was 0.32mm and 0.23mm respectively.

Discussion: A distal migration of more than 0.4mm over 2 years increases the likelihood of failure in conventional stems. The total migration of the BHR was approximately 0.3mm over a five year period, significantly less than cemented THR devices. The device is stable and this is promising for long-term survival.

E. Tsiridis M. George D. Hamilton-Baillie Z. Gamie N. Upadhyay P. Giannoudis

Without thromboprophalaxis, the recorded incidence of deep venous thrombosis (DVT) in pelvic fracture varies between 35% and 61%. The incidence of pulmonary embolism (PE) is reported to be 2–10% and death subsequently occurs in 0.5–4% of patients. With preventative measures the incidence of clinically significant DVT has been reported as low as 0.5%. The primary aim of this study is to look into the efficacy of Enoxaparin in preventing clinically significant DVT and PE in patients with pelvic and acetabular fracture. The secondary aim is to investigate the effect of prolonged pre-operative exposure to Enoxaparin on operative and post-operative bleeding. Sixty-four patients with pelvic and acetabular fractures were reviewed retrospectively between 2000–2005. Patients with coagulopathies were excluded. 40mg Enoxaparin was administered daily following haemodynamic evaluation and continued thereafter until discharge. Blood loss was measured using 3 indicators: volume of blood transfused, difference in pre and post operative Hb, and amount of blood collected in surgical drains. The incidence of clinically significant DVT was 2.9% (2 cases). There was no confirmed incidence of PE. 47% of patients were operated on within a week of admission (Group A), 40% within 1–2 weeks (Group B) and 13% in over 2 weeks (Group C). The group with the most prolonged pre-operative exposure to Enoxaparin: Group C, required the least transfused blood (A: 4.8units, B: 2.0units C: 1.3units), bled the least into drains (A:310ml, B:253ml and C:212ml) and had the smallest post-operative fall in Hb (A:2.2, B:2.0, C:1.9). The low incidence of clinically detectable DVT in the study confirms that Enoxaparin is an effective method for reducing the incidence of significant thrombotic events. Prolonged pre-operative administration of Enoxaparin does not pre-dispose patients to an increased risk of operative and post-operative bleeding.

R. Spencer M. Bishay P. Foguet D. Griffin S. Krikler R. Nelson M. Norton U. Prakash D. Pring

Introduction: Hip resurfacing has become re-established in recent years as a viable option in younger, active individuals. The results of a multi-centre evaluation of the Cormet resurfacing device are presented.

Materials and Methods: Data has been entered from 1997 onwards from 5 centres, patients being selected as suitable by 8 individual surgeons. Pre and intraoperative details recorded including indications, patient details, implant used, Harris Hip Score (HHS) and surgical approach.

Results: A total of 781 procedures in 676 patients have been recorded (54% posterior approach, 40% antero-lateral, 6% Ganz approach). The mean follow-up is 2.5 years (0.1–9.7 yrs) and the mean postoperative HHS is 85.9 (range 25–100). The mean age at surgery was 54.2 years. 60% of implantations were on male patients. The principal diagnosis was; OA 87%, RA 5%, AVN, post-traumatic OA and DDH 2% each, Perthes 1% and the remainder 1%. It is thought likely that many cases of OA had many of the above-named pathologies as a precursor. The mean maximum flexion postoperatively was 98.6 degrees. Uncemented heads (a recent innovation) were used in 7%. Kaplan-Meier survivorship is 93% at 9 years. In the OA subgroup 3.3% have been revised, approximately equal numbers for femoral head collapse, dislocation and cup loosening, but the vast majority due to femoral neck fracture, which in turn was generally associated with the posterior approach.

Conclusions: The results of this cohort (which includes the learning period of the contributing surgeons) indicate highly satisfactory outcomes in terms of HHS and implant longevity. Sub-classification of cases into those presenting abnormal anatomy and those with ‘ordinary’ OA indicates better survivorship still in the latter group. The surgical challenge varies more with hip resurfacing than with standard hip arthroplasty and this should be considered when results of surgery are reviewed. The revision options are generally much simpler than after standard THR.

D.G. Allan J.C. Milbrandt M.B. Naughton

Introduction: Metal-on-metal (MOM) hip resurfacing is becoming a more accepted and available option to consider when treating increasingly younger and more active patients. Advantages include preservation of bone stock and a larger femoral head which increases range of motion without risk of dislocation. We report here the effects of gender on revision rates in patients receiving the Cormet 2000 MOM Hip Resurfacing System.

Methods: 1058 hips were implanted in a multicenter, prospective study. All patients received a cementless, press-fit Cobalt Chrome acetabular shell with plasma sprayed titanium and HA coating and cemented Cobalt Chrome femoral head. Patients were evaluated pre-operatively through 2 years using standardized questionnaires, physical examinations, and radiographic evaluations.

Results: There were 754 males (71%) and 304 (29%) females implanted with the device. Thirty-eight (3.6%) revisions were required; 19 females (6.3%) and 19 (2.5%) males. Males had risk factors significant for revision including increased age in 10-year increments and smaller implant size. Trending but not significant (p=0.08) was lower preoperative HHS.

Discussion and Conclusion: There was a difference in revision rates between males and females, likely due to a difference in bone mass and stability. Based on these findings, the optimal patient seemed to be a larger, younger, more active male. This population has previously been identified to be at most risk after THA and utilization of a resurfacing device may be a good alternative. In addition, future studies designed to optimally select females for MOM hip resurfacing may reduce the revision rate in that population.

D.G. Allan B.K. Parsley B.W. Dyrstad R.A. Trammell J.C. Milbrandt

Introduction: Metal-on-metal (MOM) hip resurfacing releases ions locally and into the systemic circulation, raising concern for potential long term complications of elevated trace metals. This study was designed to monitor serum cobalt (Co) and chromium (Cr) levels in patients after MOM resurfacing hip arthroplasty with the Cormet 2000 prosthesis and to compare detected levels with those previously reported for hip resurfacing prostheses.

Methods: We prospectively followed patients receiving the Cormet 2000 device. Serum samples were collected at 6 months, 1, 2, and 3 years following surgery. Pre-operative controls were obtained from subjects without implants. Serum Co/Cr levels were determined using high-resolution inductively coupled plasma mass spectrometry. ANOVA was used to compare ion levels in each group. Statistical significance was set at p< 0.05.

Results: 40 subjects (25 male) were followed. Average age was 51 years (33.7–66.1). Median preoperative Co/ Cr levels were 0.27 microg/L (0.087–0.601) and 0.19 (0.014–0.576), respectively. Co/Cr levels were significantly increased at all time points when compared to preoperative levels (p< 0.001). Peak Co and Cr levels were observed at 1 year (3.26 and 4.42, respectively). At three years, the median Co and Cr levels had dropped to 2.08 and 3.55, respectively, but this was not statistically significant.

Conclusion: Elevated serum Co/Cr levels were observed at all time points following implantation. Continued elevations at three years were observed; however, the levels appear to be trending down suggestive of a “wear-in” period. Long term elevations of Co/Cr levels are concerning and will require additional studies to assess long term health risks of these levels in this population.

O. Hersche U. Munzinger

Introduction: Resurfacing arthroplasty is rapidly gaining popularity, the patients are in many cases very satisfied with the result. However some patients continue to complain about persistent groin pain, which is not clearly understood and attruibuted to different causes.

We identified femoro-acetabular impingement as a source of pain, which promptly disappeared after surgical off-set restoration.

Method: Since 2002 we implanted 390 hip resurfacing systems. At a one-year follow-up 16 patients complained about groin pain, especially when starting to walk.

In 6 patients the clinical examination and the rx could demonstrate femoro-acetabular impingement. In four cases this was due to anterior osteophytes of the femoral neck, in two cases it was due to retroversion of the femoral implant. These 6 patients were revised.

Results: During surgery femoro-acetabular impingement between these osteophytes on the femoral neck and the acetabular rim or the implant could be demonstrated. The head-neck off-set was restored with a high-speed burr. Interestingly rapid bleeding of the femoral neck was noted in all cases confirming the presence of vital bone. After surgery five of the six patients were painfree after 6–12 weeks. One patient did not experience a difference until now. There were no femoral neck fractures seen after this procedure.

Conclusion: Femoro-acetabular impingement seems to be a common source of persistent groin pain after hip resurfacing. Care has to be taken to restore the head-neck offset during implantation.

P.A. Vendittoli R. Boddu Siva Rama A.G. Roy M. Lavigne

Introduction: Heterotopic ossification (HO) occurs commonly after total hip arthroplasty (THA). Its severe form can result in impaired range of motion with reduced functional outcome. The rate and severity of HO after hip surface replacement arthroplasty (SRA) have never been well studied.

Methods: Two hundred and ten hips (194 patients) were randomized to receive uncemented metal-on-metal THA (103) or metal-on-metal SRA (107). Standard antero-posterior radiographs of the pelvis were assessed for HO by 2 reviewers at the latest follow-up (minimum of 6 months), using Brooker severity grading and Kjaersgaard-Andersen regional classification.

Results: Pre-operative and post-operative data were similar for both groups. The incidence of HO was 38.5% in the SRA group compared to 32.6% in the THA group (p=0.5). However, there was a significant difference in severity grades for the 2 groups (chi square, p=0.02). According to Brooker_s classification, nearly half of HO was of grade 2 in SRA and of grade 1 in THA. SRA was associated with significantly higher rates of severe HO (grades 3 and 4) than THA (12.5% vs. 2.2%; p=0.009). Inter-rater agreement for Brooker grading was excellent (Cohen_s kappa, 0.88; p< 0.01). HO in SRA involved both the central and lateral regions in 26% of cases, whereas only 3% of HO in THA showed such a pattern (p=0.025). Risk factors, such as male gender, osteoarthritis, bilateral predilection, and previous history of HO, were observed in both groups. Patients with HO had reduced internal hip rotation (16.4° vs. 22.2°; p=0.02) and a higher incidence of postoperative hip pain (52% vs. 30%; p=0.04), but comparable functional outcome scores.

Discussion: The incidence of HO after hip arthroplasty seems to be determined by patient-related factors. However, HO severity appears to be associated with local surgical factors and thereby SRA may result in more severe HO than THA. An extensive surgical approach, additional soft tissue release and the blunt damage occurring in gluteal muscles with SRA may signal the induction of more severe HO. Peri-operative deposition of bone debris derived from femoral head preparation may also play a role by transplanting osteoprogenitor cells. Surgeons must be aware of this risk of severe HO when offering SRA as an alternative treatment to younger patients. Routine prophylaxis with NSAIDs needs to be considered in these patients. A meticulous surgical technique to reduce muscle damage, pulsed lavage to clear bone debris, and debridement of necrotic tissue, may help to decrease the risk of severe HO in SRA.

K. Sisak R. Villar

Introduction: A common criticism of the modern hip resurfacing arthroplasty is its high early complication rate, in particular femoral neck fracture, displacement of the acetabular component and avascular necrosis. The overall complication rate varies widely in different published series. The sometimes alarmingly high rate of complications, as much as 22% for femoral neck fractures alone (Mont et al. 2005), has deterred many surgeons from using resurfacing implants. As a specialist elective hip practice we wished to specifically determine the early complication rate of hip resurfacing arthroplasty using the metal-on-metal Cormet 2000 implants. We defined an early complication as any resurfacing procedure which required inpatient readmission and/or further intervention within 12 months of the primary operation.

Material and methods: We assessed 253 consecutive hip resurfacing procedures (226 patients). All procedures were performed by the same surgical team using the same surgical approach (posterolateral). Operations were performed between 2001–2005. The mean operating time for was 51.8 minutes. The mean age of patients was 50 years (27 to76) at the time of surgery. 141 patients (62.4%) were male and 85 (37.6%) were female. The preoperative diagnosis was osteoarthritis for the majority of patients 246 (97.2%), the remainder having avascular necrosis (4 cases, 1.6%), chondrolysis (2 cases, 0.8%) or large osteochondral defects (1 case, 0.4%).

Results: In this series there were two infections (one superficial and one deep), one intraoperative femoral neck fracture (converted to THR), no episodes of avascular necrosis, one revision because of acetabular component loosening and one readmission because of a postoperative haematoma 10 days after surgery. All together two patients needed a further operation within one year of the primary operation (one two-stage revision because of deep infection, one revision to THR because of acetabular component shift). The haematoma was treated conservatively. There was one deep vein thrombosis (DVT), one case of iliopsoas tendonitis, one case of trochanteric bursitis and one patient wore an abduction brace for 6 weeks because of slight instability although there was no dislocation. The patient with DVT was readmitted as an inpatient. The overall complication rate (readmission as an inpatient) was 1.6% (4 patients) with the Cormet 2000 implant. Reoperation rate was 1.2% (3 patients) (including the intraoperative conversion to THR).

Discussion: The Cormet 2000 is a fully uncemented hydroxy-apatite coated hip resurfacing implant. In our series we found a low early reoperation and infection rate. All the reoperations were performed for cases were the primary operation was carried out in the first 6 months of this series. There were no complications associated with the uncemented femoral component of the Cormet 2000 implant.

L. Marega M. Morlock G. Baroncelli M. Hahn G. Delling

The idea of resurfacing the femoral head instead of removing it has been attractive for a long time.

Unfortunately the results have been invariably poor if compared with contemporary available conventional hip prosthesis. In the last decade metal on metal technology with very accurate manufacturing made hip resurfacing a viable option. The main complication of this operation is early failure due to femoral neck fracture. This event is still incompletely understood and probably multi-factorial. Accurate placement of the femoral component to avoid notching the femoral neck, cementing technique to avoid over-penetration of the cement, small implantation forces and careful soft tissue handling to minimize the damage to the bone vascularity are thought to be the main issues. The ideal candidates for this operation are young and active patients because they have good bone quality and will take advantage of the improved performances that hip resurfacing can offer.

Unfortunately young men are also the group of patients at higher risk for the formation of heterotopic ossifications.). To prevent this complication radiotherapy was administered in a single dose of 6 Gy with two opposite fields of 18 MV generally the first post operative day. When we started to perform hip resurfacing we did not consider changing our protocol. Between March 2004 and May 2005, 55 hip resurfacings were performed using the ASR implant (DePuy) by a single surgeon (LM). Most males under the age of 60 received radiotherapy. There were 4 femoral neck fractures in the 23 male patients who received radiotherapy (17.3 %) and 1 fracture in the 32 patients who did not receive radiotherapy (3.1 %, Chi-square test: p= 0.07). All the fractures occurred between the 90th and the 120th postoperative day. No fractures were reported in the 12 women included in this study. What arouse our attention was the unacceptably high number of femoral neck fractures. The learning curve alone could not explain what was happening. At first the radiotherapy was not considered at all as factor but errors in the surgical technique were looked for. The clue came from the observation that there were no women in the fracture group in spite of the fact that the surgical technique was the same and also in spite of the fact that women should be at higher risk due to poorer bone quality as shown in the literature. This led us to check the incidence of fractures in the radiotherapy and in the non radiotherapy group. At this stage things became quite clear. Subsequently the histology of the specimen was re-examined with regard to this factor. Bone necrosis of the femoral head in the patients who underwent radiotherapy was much more pronounced then in other failures which show different degrees of necrosis. In conclusion there are strong indications that radiotherapy of the femoral head should not be performed in combination with hip resurfacing.

C. Lautridou B. Lebel G. Burdin S. Leclercq C. Vielpeau

Background: Early or later dislocation is a frequent complication associated with total hip arthroplasty. The Bousquet’s acetabular component, an original concept of dual mobility socket has been used, for increase stability and mobility. The first mobility is between the femoral head and the polyethylene insert, and the second mobility between the polyethylene and the metal cup socket. The cup, covered with alumina was impacted without cement. The purpose of this study was to evaluate the long-term results of a retrospective series of primary arthroplasty with this cup and a cemented Charnley type femoral component.

Materiel and methods: This study included 437 hip replacements performed between 1984 and 1990, in 389 patients with osteoarthritis (62.5%), dysplasia (11.4%), necrosis (8%), rheumatoid arthritis (5%), post-traumatic and others (13.1%). The average age of the patients at the time of the index procedure was 61 years. The patients were followed at routine intervals for clinical and radiographic review. The clinical results were appreciated with Postel–Merle d’Aubigne score (PMA). Osteolysis was noted according to Gruen zones.

Results: The outcome is known for 345 hips (79%): 164 alive without revision at a mean of 16,5 years follow-up, 137 died without revision, and 44 failures. 92 (21%) were lost at follow up. Revision, for aseptic loosening of femoral or acetabular component, was performed in 30 hips(6.8%). 5 dislocation occurred and were revised: 2 early regarding to technical errors and 3 after 10 years or more of follow up. 7 hips were revised for deep infection, and 2 for unaccountable pain.

At more than 15 years follow-up, the mean PMA hip functional score was 17.1. 66% of the hips was A, 4% were B and 30% were C according to the Charnley’s score. Of the 164 hips in the patients who had survived at least 15 years, 28 had femoral osteolysis in zone 7, and 31 had femoral osteolysis in one (or more) of the other 13 zones. 6 hips had an impingement sign on the neck of the femoral component, without aseptic loosening.

According to Kaplan-Meier analysis, the fifteen year survival rate, was 84.36% with revision for any reason (infection, dislocation, osteolysis…) for end point. The young age of the patients at the time of the index surgery is correlated with loosening.

Conclusion: The long term results of the press fit, double mobility socket with cemented Charnley type femoral stem are good. The prevalence of revision for dislocation is very low in our series. But this concept do not avoid wear, osteolysis and aseptic loosening, specially in young active patients. We can recommand this type of prosthesis for patients over 70 years, and/or with high risk of dislocation.


The topic of this study was to research the survival rate of ATLAS hip prosthesis (acetabular cup) performed by one operating surgeon only and with a minimum of 10 years follow up.

Material and method: The ATLAS cup was hemispheric, in titanium alloy TA6V4, with a thin layer (2.5mm). It had a large central orifice as well as a radial slot allowing a certain elasticity enabling a pressfit impaction. Between January 1989 and December 1995, 297 ATLAS were implanted in the Clinique Saint André of Reims, 171 ATLAS II non hydroxyapatite coated and 126 ATLAS III hydroxyapatite coated. There were 176 women (59,2%) and 121 men (40,8%). The average age was 66 (20 to 94).

Each patient was contacted by phone to find out if the prosthesis was still in place or whether a new operation had been performed. For the deceased patients, the family or the usual doctor were contacted by phone to answer the question with a maximum of details.

The non-parametric survival rates were performed using the actuarial method according to Kaplan-Meier. The results were given with a reliability rate of 95%. The PRISM program was used.

RESULTS: On the 1st of January 2006, out of the 297 patients present at the start, 38 patients (12,8%) could not be contacted, 70 patients (23,5%) had died, 35 were reviewed and 120 answered the phone inquiry.

32 patients had undergone a revision: 23 due to the cup: there were 15 cases of wear of the polyethylene, 4 osteolysis, 3 cases of recurring dislocation and a secondary tilt of the cup, 5 cases of acetabular and femoral revision for 4 femoral loosening (change of cup by principal) and 4 cases of revision of the femoral components only.

The survival rate of the global series of 297 ATLAS (coated and non coated with hydroxyapatite) taking into consideration only the revisions due to the acetabular cup (wear of polyethylene, wrong position) was evaluated at 90% after 10 years and 85,5% after 15 years.

The results were better for the ATLAS III coated in hydroxyapatite: 92,3% after 10 years and 88,4% after 14 years, which confirms the advantages of this surface treatment. In this series, the revision rate for wear of the polyethylene was less important (3%)

With a maximum of 17 years follow up no mobilisation of the insert in the cup had been observed and no metallosis.

Conclusion: The survival rate of the global series of 297 ATLAS (coated and non coated with hydroxyapatite), taking into consideration only the revisions due to the cup (wear of the polyethylene, wrong position) was of 90% after 10 years and 85,5% after 15 years.

The rate was higher for the ATLAS III coated with hydroxyapatite: 92,3% after 10 years and 88,4 % after 14 years, which confirmed the advantages of this surface treatment.

Full Access
G. von Foerster

The short stem titanium prothesis preserves the femoral neck. No reamer and no rasp is used for the implantation. Two times compression of the bone with a compressor and with the prothesis it self continues the principle of bone retention.

Preserving the femoral neck and compression of the bone lead to an high anchorage and the best primary stability. This is mandatory for safe osseo integration.

Except metal on metal all combinations are suitable. Deltaceramic-Deltaceramic is the most modern possibility.

The high anchored short-stemp leaves enough virgin-bone for any standard prothesis in case of later revision. In 1999 implantation of CFP Prothesis was started in the Endoklinik-Hamburg. Until 2005 2500 prothesis were implanted. A five year follow up of the first hundert cases does not show system corellated failures. An overview of 2400 implants shows a revision rate of 1%. Total exchange procedure was necessary in 8 cases because of deep infection (0,33%). Only very few none fixed stems and cups had to be reviced.

Minimal invasive surgery is well suitable. In our clinic we prefer the posterior aproach.

With six sizes left and right nearly all tipe of bone shape is covered.

Extreme varus or valgus hips are not indicated as well as severe deformaties.

The CFP Prothesis is an good alternative to the CUP Prothesis especially for the young patients with femoral head necrosis which we see in about 10%.

A five year follow up is only really interessting if it has bad results, with goog results it gives us confidence to wait for the ten year results.

K. Zweymüller M. Steindl U. Schwarzinger M. Brenner

Intruduction: Cementless cup anchorage for total hip replacement is among the techniques widely accepted today. Attention focuses on hemispheric cups mimicking the anatomical shape of the bony acetabulum. However, the first-generation cementless hemispheric cups had a number of design flaws, which have meanwhile been attended to. We therefore never really turned away from threaded cups and began to implant a cone-shaped version of commercially pure titanium in January 1985. Introduced in January 1993, the redesigned version was unlike any other implant described in the literature in terms of its outer shape, the locking mechanism for the polyethylene liner, the cutting strength of its teeth and the thin wall of the cup shell. We wanted to know whether this implant was generally applicable for all primary THRs irrespective of the underlying anatomy, i.e. whether the exclusive consecutive use of this implant was justified.

Method: Between 1/1/1993 and 30/4/1994, 332 patients underwent primary surgery for osteoarthritis with threaded cups and titanium stems. These self-tapping double-cone cups made of pure titanium feature sharply cutting teeth for anchorage without screws. The PE liner locks into the titanium shell by a 4-level conical locking mechanism obviating the need for indentations for rotational adjustment of the liner. All cups and stems implanted during this period were uncemented. At 10 years plus, clinical and monitor-controlled radiologic follow-ups were conducted to evaluate changes in cup position, radiolucent lines, osseo-integration and revisions.

Results: 209 patients (63 males and 146 females; mean age at surgery: 62.6 years, range: 18.9 to 83.2 years) showed up for follow-up. 71 were dead, 36 without revisions were contacted by phone, 10 were lost to follow-up. The mean follow-up time was 10.2 years (range: 10.0 to 11.1 years). 2 patients had undergone cup revision, one for low-grade infection after 9.6 years and one for cup fracture after 5 years. With cup revision as the endpoint, the Kaplan-Meier survival rate was 99,2 % (CI: 96.6 to 99.8). Radiography showed altered cup inclination in two patients and radiolucent lines signalling absence of osseointegration in one patient. All other implants were stable clinically and radiologically. Gaps between the cup floor and the bone tended to be spontaneously obliterated by newly formed bone. Complete obliteration was observed even in cases with incomplete cranial implant coverage due to hip dysplasia.

Conclusion: The outcome of threaded double-cone cups at 10 years and more compares well with the best results achieved with other implants, particularly hemispheric cups. This documents that their unique design features have so far stood the test of time. It also shows that these cups have a place in all patients candidates for primary total hip arthroplasty.

P. Zenz H. Knechtel G. Titzer-hochmaier W. Schwägerl

Introduction: The Allofit cup is a hemispherical pressfit cup with a flattened pole for cementless implantation. Clinical use started in 1993 and we report our clinical and radiographic results of the first 100 cases. 75 hips of this group have been followed during the first 3 to 4 years using EBRA for migration analysis. These results also are presented.

Material: Out of 100 hips 81 have been followed mith a mean of 10,1 years (9,8–11). 6 patients died, 11 did not show for follow up an 1 patient had a revision for deep infection with two-stage exchange meanwhile.

The initial diagnosis was primary coxarthrosis in 63, rheumatoid arthritis in 10, congenital dislocation of the hip in 5 and necrosis of the femoral hed in 3.

In all cases the cementless Alloclassic stem was used, as bearing material metasul was implanted in 73 and ceramic-polyethylene in 8 cases.

Complications: For prolonged exsudation from the wound one soft tissue revision was necessary. 2 luxations were treated conservative. One early deep infection healed after synovectomy and irrigation, one late deep infection was cured by a two stage reimplantation.

Results: The EBRA migration analysis after 3,6 years (2,3–4,2) showed cranial migration of 0,35 mm (0,2–0,6 mm), medial migration of 0,25 mm (0,10–0,40 mm) and a calculated total migration as a combination of both of 0,45 mm (0,22–0,72). Therefore at this time there was no evidence of early loosening or migration indicating later loosening.

The preoperative Harris hip score was 53,13 pts (23–73), the postoperative score after 10 years 96,5 (78–100).

Radiographic evaluation after 10 years showed no lucencies in 78 of 81 jpints. 3 hips had a lucent line of 1mm in zone III. We detected no signs of osteolysis, loosening or migration.

No reoperations for any reason exept 2 septic cases have been performed yet.

Summary: After 10 years the clinical and radiological results of this implant are very satisfying. These results confirm the early observations of a migration analysis performed 6 to 8 years before.

P. Mertl J. Vernois E. Havet A. Gabrion

Introduction: Modular necks used during primary or revision total hip arthroplasties permit to restor the ideal femoral offset and arm of abductors muscles, to ajust leg length and to reduce impingment between the neck and the socket with good hip balancing.

Material and methods: Modular necks are titanium implants manufactured with a double Morse taper: one cylindrical for the junction with the head, and one flat for the junction with the stem. They are avalaible in 2 lengths (short and long) with 6 different geometries: straight (CCD:135°), antevreted of 8° or 15°, 8° and 15° of varus (CCD: 127° and 120°), and a combination of anteverted and varus neck.

362 revision and 920 primary THA were performed with a minimal of 5 years follow-up in the Orthopaedic Department of Amiens University Hospital with modular necks.

Results: 23 patients died and 11 were lost of follow-up. None rupture was deplored. Femoral offset was restored in 97% of these cases even in the revision surgery, end equalization of leg length was obtained in 98% of the patients. Residual Trendelemburg sign was noted in 37 patients, always after revision. The rate of dislocation was low with 2% because of the absence of impingment.

Discussion: Because proximal femoral geometry is different for each patient and femoral offset independent from the IM canal diameter, modular neck is one easy solution to restor independent parameters. In addition, the per-operative trials permit to choose the best implant to avoid any impingment, reducing the risk of dislocation and increasing the range of motion. It’s ideal now for the use of hard bearings. Laboratory analysis have demonstrated very good resistance in assembly-distraction, deep flexion and rupture tests. No corrosion was noted and retrieved weight loss was minimal.

L. Zagra M. Corbella R. Giacometti Ceroni

Background: Acetabular dysplasia is a congenital deformity that leads to hip osteoarthritis. The reason is the abnormal load transfer on the head which causes the cartilage damage and the progressive lateralization of the rotation centre of the head. The reorientation spherical periacetabular osteotomy, introduced by H. Wagner in 1976, has the aim to normalize the acetabular parameters increasing the coverage of the femoral head. The original indication of the author was the correction of the insufficient acetabulum in young adult patients, just after the closure of the triradiate cartilage, in which it is possible a functional adaptation of the osteotomized hip.

Materials and Results: This surgical procedure has been performed in the First Division of Galeazzi Orthopedic Institute of Milan Italy, since 1979 (180 cases up today).

The hips operated before 1985 were 14. The patients were 10, in 4 cases the operation was bilateral. There were 9 females and 1 male. The average age of the patients at the time of the operation was 19.3 years. All the patients had a DDH without X-ray signs of osteoarthritis and had a mild or absent pain. In 9 cases the isolated periacetabular osteotomy was performed and in 5 cases a femoral varus osteotomy was associated at the same time. The osteotomies were Wagner type I in 12 cases and Wagner type III in 2 cases.

We always used a Smith-Petersen approach. The periacetabular osteotomy was made by special spherical chisels of different diameter under X-rays control. The fixation of the osteotomy was made in 8 cases according to the original technique with a special double horn plate fixed by screws to the ileum and in 6 cases only with the help of Kirsches wires, as actually we prefer.

10 cases with a clinical and X-ray follow-up longer than 20 years have been controlled. 4 cases are lost to follow-up. Occurrence and type of pain, walking, limp, range of motion were evaluated. Wiberg CE angle, signs of osteoarthritis and centre of rotation of the head are observed on the X-rays.

Discussion: Evaluating the results, natural history of DDH must be considered. The revision of long term results (follow-up longer than 20 years) shows that it is possible to obtain good clinical outcome in the prevention of arthritis and on patients’ symptoms. The indication must be strictly followed: full indication is maintained in dysplasia of the adolescent, indication in the young adult only if some symptoms are present, very rare indication in patients with signs of arthritis and only in very mild cases. As a matter of fact in a group of patients with a shorter follow-up that is not part of this study, in which the indication was extended to Tonnis 1–2 arthritis we had much more bad results and complication. We observed generally worst results with obese patients.

M. Tannast S. Mistry S. Steppacher F. Langlotz G. Zheng K.A. Siebenrock

Introduction: It could be shown that an ample number of classical hip parameters for radiographic quantification of hip morphology on anteroposterior (AP) pelvic radiographs vary significantly with individual pelvic tilt and rotation. This could be proven not only for classical hip parameters (e.g. the lateral centre edge angle) but also for more recently described radiographic features such as acetabular retroversion. The resulting misdiagnosis and misinterpretation can potentially impair a correct therapy for the patient.

We developed fast and easy-to-use computer software to perform three-dimensional (3D) analysis of the individual hip joint morphology using two-dimensional (2D) AP pelvic radiographs. Landmarks extracted from the radiograph were combined with a cone beam x-ray projection model and a strong lateral pelvic radiograph to reconstruct 3D hip joints. Twenty-five parameters including quantification of femoral head coverage can be calculated for a neutral orientation. The aim of the study was to evaluate the validity of this method for tilt and rotation correction of the acetabular rim and associated radiographic parameters.

Methods: The validation comprised three steps:

External validation;

internal validation; and

intra-/interobserver analysis.

A series of x-rays of 30 cadaver pelves mounted on a flexible holding device were available for step 1 and 2. External validation comprised the comparison of radiographical parameters of the cadaver hips when determined with our software in comparison with CT-based measurements or actual radiographs in a neutral pelvic orientation as gold standard. Internal validation evaluated the consistency of the parameters when each single pelvis was calculated back from different random orientations to the same neutral pelvic position. The intra-/interobserver analysis investigated the reliability and reproducibility of all parameters with the help of 100 randomized, blinded AP pelvic radiographs of a consecutive patient series.


All but one parameter (acetabular index) showed a substantial to almost perfect correlation with the CT-measurements.

Internal validity was substantial to almost perfect for all parameters.

There was a substantial to almost perfect reliability and reproducibility of all parameters except the acetabular index.

Conclusion: The software could be shown to be an accurate, reliable and reproducible method for correction of AP pelvic radiographs. This computer-assisted method allows standardized evaluation of all relevant radiographic parameters for detection of anatomic morphologic differences. It will be used to study the influence of pelvic malorientation on the radiographic appearance of each individual parameter. In addition, it allows evaluating the clinical significance of standardizing pelvic parameters.

B.M. Devitt J.S. Butler J. Street D. McCormack J. O’Byrne

Aims: A retrospective review of all periacetabular osteotomies (PAO) performed at a general elective orthopaedic Hospital over a 7-year period. To assess the clinical, functional and radiographic outcome associated with PAO when introduced as a new procedure to a non-super-specialised regional centre.

Methods: A retrospective review of 85 PAOs performed on 79 patients at Cappagh Hospital between 1/4/1998 and 1/4/2005. The medical records and radiographic images of all patients were reviewed. Clinical follow-up evaluations were also performed.

Results: 85 PAOs were performed on 79 patients. Mean age at time of surgery was 22.9 years (range, 14–41 years) with an increased preponderance of females (F:M=10:1) and right sided hip involvement (R:L=1.1:1). The mean Merle D’Aubigne and Postel hip score increased from 12.4 (range 9–14) preoperatively to 16 (range 11–18) postoperatively (P< 0.0001). The average lateral center edge angle increased from 5° preoperatively to 26° postoperatively (P< 0.0001). The anterior center edge angle averaged 6.6° preoperatively and improved to 34.4° postoperatively (P < 0.0001). The acetabular index angle decreased from an average of 24.8° preoperatively to 8.4° postoperatively (P< 0.0001). At clinical follow-up, 77% of patients had no/mild pain, 30% of patients had a limp and 64% of patients were unlimited in physical activity.

Conclusions: The short term results in this group of patients treated with PAO show reliable radiographic correction of deformity and improved clinical scores. We suggest that PAO may safely be carried out at a non-super-specialized institution provided the surgeons have sufficient experience and patients are selected appropriately.

M. Tannast S. Mistry S. Steppacher G. Zheng F. Langlotz K.A. Siebenrock

Introduction: Recently, the correct interpretation of anteroposterior (AP) pelvic radiographs has regained increased attention, particularly in the field of joint preserving hip surgery. The diagnosis of acetabular retroversion associated with femoroacetabular impingement or hip dysplasia is made regardless the individual pelvic orientation due to the lack of a method of correction. Furthermore, it is known that a substantial number of the most common radiographical hip parameters can vary with the individual pelvic orientation. The goal of the study was to evaluate which parameter can be measured accurately on an AP radiograph.

Methods: Digital AP pelvic radiographs of 100 consecutive hips were used for evaluation. The blinded and randomized x-rays were examined by two independent observers with special software that has been validated previously. The software is able to correct the projected acetabular rim and the associated parameters for pelvic malpositioning. The following parameters were investigated: femoral head coverage in craniocaudal and anteroposterior direction (in total and for each single quadrant of the femoral head), the lateral center edge angle, the acetabular index, the ACM-angle, the extrusion index, the cross-over sign, the retroversion index, and the posterior wall sign. All parameters were first measured regardless to the individual tilt and rotation. These non-standardized values were then compared to the standardized values for a neutral pelvic orientation. This was defined with a pelvic inclination of 60 degrees which was detected with one single strong lateral pelvic radiograph.

Results: There were no differences in evaluation of the radiographs between the two observers concerning the significance of standardized and non-standardized values for the measured features. All but three parameters were significantly different when measured to the anatomically reference neutral orientation. The only parameters that did not change after standardization were the total femoral coverage, the acetabular index and the ACM.

Discussion: Except from the ACM and the acetabular index, basically all parameters change when standardized to a neutral orientation. Although from a statistical point of view, the total craniocaudal femoral coverage did not change, it is likely that this is due to an inverse effect of the anterior and posterior part of the acetabulum. We conclude that the most common hip parameters can not be reliably measured without standardization. It remains to be proven that the standardization of the parameters correlates with the clinical symptoms.

J.B. Czubak M. Tyrakowski S. Pietrzak

Improvement in coverage achieved by double or triple osteotomies is limited by the size of the acetabular fragment and the ligaments connected with the sacrum. Correction is achieved with the notable asymmetry of the pelvis. In periacetabular Ganz osteotomy (PAO) the acetabular fragment has no connection with the sacrum, which creates enormous possibilities for correction, leaving the pelvic ring untouched.

The aim of the study is to present our experience and early results of using PAO in the treatment of hip dysplasia in adolescents and young adults who were previously treated operatively in childhood, and to find the technical and clinical impact of previous operations on our Results: In the years 1998–2005 262 periacetaubular osteotomies were performed in our hospital. All the patients were operated by one surgeon (JC). From this group 41 patients (43 hips) had previously been operated in childhood for the treatment of hip dysplasia. The previous treatment consisted of: open reduction in 10 hips, DVO in 14 hips, pelvic osteotomy (Salter, Dega, Chiari) in 8 hips, combined: open reduction+DVO+pelvic osteotomy in 10 hips, greater trochanter transfer in 3 hips, bone lengthening in 4 hips, acetabular cyst removal in 1 hip. The age at the primary operation ranged from 1–20.. The follow-up period ranged from 1–7,5 ys av. 2 ys.

In 31 hips the Smith-Petersen, and in 12 hips ilioinguinal approach were performed.

Methods. In clinical pre-op, and post-op examination the following factors were considered: pain, limping, Trendelenburg sign, range of motion, length discrepancy. Radiographic pre-op and post-op examination consisted of: AP view of the pelvis, false profile and AP view with the leg in abduction. Classic and anterior CE angle were measured. During the last examination Harris Hip Score was used.

Results. Flexion slightly decreased from pre-op. 90–140° (av. 118°) to 80–130° (av. 104°) post-op. abduction remained unchanged 15–60° (av. 40°) and 15–60° (av. 40°) respectively, adduction slightly increased 15–40° (av. 31) and 20–50° (av. 33°). The range of rotation did not change after the operation. The sign of Trendelenburg was found in 27 hips before operation and in 8 hips post-op. Pain (acetabular rim syndrome) was found in 40 hips before operation and in 4 hips after the surgery. Either classic or anterior CE angle increased after the surgery in all cases from −14° to 34° and from −10° to 35° respectively. We had a rather low complication rate. But in cases previously operated and in males we strongly recommend Smith-Petersen approach extended into the frontal part of the hip for a better exposure in the scarred and hardened tissues.

We find the technique of PAO as a safe, and effective tool for treating hip joint pathology increasing treatment possibilities for hip joint preservation.

I. Mechlenburg S. Kold L. Romer K. Soballe

Background and purpose. At the Ganz periacetabular osteotomy the osteotomized acetabular fragment is reoriented in an adducted, extended and rotated position. Two screws fixate the acetabular fragment and the patients are allowed 30 kg weight bearing immediately after surgery. We were interested in examining the stability of the reoriented acetabulum after the Ganz osteotomy and accordingly the migration of the acetabular fragment was assessed by radiostereometry.

Methods. Thirty two dysplastic patients (thirty two hips), twenty seven females and five males were included in the study. Median age was 39 (20–57) years. Radio-stereometric examinations were done at one week, four weeks, 8 weeks and six months. Data are presented as mean with 95% CI.

Results. Six months postoperatively, the acetabular fragment had migrated 0.7mm (0.4–1.0mm) medially, and 0.7mm (0.5–0.9 mm) cranially. Mean rotation in valgus direction was 0.5° (−0.1–1.0°). In other directions, migration was below 0.4. There was no statistical difference between migration 8 weeks and 24 weeks postoperative in translation or rotation.

Interpretation. This is the first paper dealing with radio-stereometric analysis in Ganz osteotomy. Due to the very limited migration, we find our postoperative partial weight-bearing regime safe.

R. Biedermann L. Donnan A. Gabriel R. Wachter M. Krismer H. Behensky

Periacetabular osteotomy (PAO) is a well established method to treat hip dysplasia in the adult. There are, however, a number of complications associated with this procedure as well as a time related deterioration in the grade of osteoarthritis that can influence the long term result. It is essential that patients are fully informed as to the effectiveness of PAO, the likelihood of complications and their influence on the subjective outcome prior to giving consent for surgery. Generic outcome measures offer the opportunity to determine treatment efficacy and the influence on the outcome by complications.

60 PAOs on 50 patients were investigated retrospectively after a mean follow up of 7.4 years. The patients’ self reported assessment of health and function was evaluated by the SF-36 and the WOMAC questionnaires at last follow-up. 40 healthy persons served as a control group.

The centre-edge angle improved from a mean of 8.7° to 31.5°. The weight bearing surface improved from a mean lateral opening of 8.7° to 4.2°. The degree of osteoarthritis improved in one case, remained unchanged in 20 and deteriorated in 17. There was a tendency of higher CE-angles towards a higher rate of deterioration, indicating that overcorrection may increase osteo-arthritic degeneration. 13 of the 60 interventions had no complications. Minor complications occurred in 25 (41%) interventions and in 22 (37%) at least one major complication occurred. SF-36 summary measure was 76.4 for PAO patients and 90.3 for the control group. Mean WOMAC score was 25.1. The severity of ectopic bone formation, incidence of postoperative peroneal nerve dysfunction and delayed wound closure did not influence the subjective result. Patients with major complications had a similar subjective outcome as patients with minor or no complications, but persistent dysesthesia due to lateral femoral cutaneous nerve dysfunction led to a worse subjective function as assessed with the WOMAC score.

P. Bernstein F. Thielemann K. Günther

For the prevention of premature osteoarthritis of the hip, the periacetabular osteotomy (PAO) of Ganz has become a common procedure. Though being a powerful method for obtaining large correction angles its drawback is the need for a broad exposure, resulting in more or less disfiguring scars. We modified the surgical approach to PAO by using two small skin incisions and reduced the extent of deep exposure by leaving the rectus femoris tendon in place and avoiding larger peri-articular deep soft tissue release.

The aim of this study is, to compare the early clinical and radiographic results of this less invasive approach with the conventional Smith-Peterson approach.

Patients and Methods: Between 01/04 and 05/05 22 consecutive PAO were performed through a conventional Smith-Peterson approach (group A). After introducing the less invasive technique 22 PAO were performed between 09/04 and 11/05 (group B). All patients were operated by the same experienced surgeon. Patients age ranged from 14 years to 46 years (mean age 26 years). Clinical (i.e. Harris-Hip-Score, Vancouver Scar Scale) and radiographic examinations (i.e. CE-angle) were performed preoperatively and postoperatively at an average follow-up of 16 months (range 6–29 months).

Results: Mean CE-angle correction in group A was 17° and in group B 23°. Functional improvement, as rated by the preoperative to postoperative Harris-Hip-Score-difference, was 15 points in group A and 22 points in group B. After the less-invasive approach, scars were considerable smaller and better-rated by the Vancouver Scar Scale (3 versus 4 after conventional surgery). The number of transient lateral cutaneous femoral nerve lesions was the same in both groups. The average time of surgery was 135 min. in group A and 153 min. in group B.

Conclusion: A smaller skin incision and limited soft tissue exposure improves cosmetic results after PAO without influencing the extent of acetabular correction negatively. The early and mid-term postoperative functional results, however, could not be significantly improved by the less invasive approach.

A. Troelsen B. Elmengaard K. Søballe

Introduction: Minimal invasive surgery (MIS) seems to be part of future orthopaedic solutions. Currently, most approaches for the Bernese periacetabular osteotomy (PAO) are characterized by relatively extensive incisions, dissection and detachment of muscles. We have developed a new MIS approach for the Bernese PAO. The purposes were to reduce patient morbidity and to improve the cosmetic result following surgery without negatively influencing the achieved reorientation of the acetabular articular surface. In this study we present the surgical technique, results and compare them to the ilioinguinal (II) approach.

Methods: The new MIS technique is a trans-sartorial approach using a three inch skin incision. Previously the II approach was used. From 1999–2006 a total of 215 patients with acetabular dysplasia were operated by the same surgeon in two successive time periods with the II (97) and the trans-sartorial (118) approaches. No supplemental surgery was performed. The two approaches are retrospectively compared regarding perioperative measures, transfusion requirements, complications and the achieved reorientation of the acetabular articular surface. Data are compared by Kruskal-Wallis Test and are presented as median and interquartile range.

Results: The trans-sartorial approach significantly reduced days of admission (8 days (7–9) vs. 10 days (8–13), p< 0.0001), duration of surgery (70 min (60–75) vs. 100 min (82.5–120), p< 0.0001), perioperative blood loss (200ml (150–350) vs. 450ml (325–700), p< 0.0001) and the percentage of patients receiving blood transfusion (18.6 % vs. 3.4%). Of severe neurovascular, infectious and technical complications none occurred in the trans-sartorial group and 3 cases of arterial thrombosis were seen in the II group. The achieved reorientation measured by the CE-angle postoperatively had median values of 31° (25–36) in the II group and 33° (29–36) in the trans-sartorial group, p=0.016. The postoperative AI-angles were 10° (2–14) and 3° (0–7) in the II and trans-sartorial groups respectively, p< 0.0001.

Discussion: Our shift to the trans-sartorial approach was rewarding as the duration of surgery, perioperative blood loss and transfusion requirements were reduced. The new MIS technique is safe and improves the cosmetic result without negative influence on the achieved reorientation of the acetabular articular surface.

R.M. Gillies M. Hogg S.M. Donohoo W. Schmidt J. Racanelli

Introduction: Bone resorption at the bone-implant interface is still a problem, leading to pain, poor function and the possibility of bone fracture. This loss of supporting bone tissue is due to resorption and impaired bone formation. Loosening of an implant is often not clinically or radiographically apparent for 8–10 years. It would be beneficial if these potential failures could be identified early so that revision surgery can be avoided. The aim of this study was to investigate the influence of implant material property changes and its influence on the trabecular loading patterns of the underlying supporting bone structure.

Methods: An intact and reconstructed 3D finite element (FE) model of a human femur was developed. The model was generated using PATRAN and CT scans. This was used to determine the stress, strain and interface sliding of a knee implant at heel-strike and stair climbing phases of gait. FE analysis of the model was performed using ABAQUS software. The materials properties of the bone were extracted from the CT data and applied using FORTRAN subroutines. Implant-bone interfaces were simulated using cementless fixation concepts. Sliding contact conditions were applied to simulate the immediate post-operative period.

Results: Three material property cases were analysed, with respect to the intact bone, at 100%, 25% and 2.5% of cobalt chrome’s (CoCr) Youngs modulus. At heel-strike, for the 100% case, higher stress was found at anterior flange while lower stress dominated around the pegs and intercondylar notch. For the 25% case, lower stresses were found in the intercondylar notch and higher stresses above the pegs. For the 2.5% case, stresses resembled that of intact bone, higher stresses were found above the pegs and lower stress in the intercondylar notch. In stair-climbing, for the 100% case, lower stresses were found around the pegs and in the intercondylar notch. For the 25% case, lower stresses were found in the intercondylar notch and higher stresses in areas above the pegs. For the 2.5% case, higher stresses were found at the distal condyles and lower stresses were observed in the intercondylar notch.

Discussion: The analysis presented changes in the trabecular loading and subsequently resulted in stress shielding. The general trend showed that the majority of stress shielding is occurring at the posterior flange and medial condyle while increased trabecular loading occurred at the anterior flange and lateral condyle regions. As the stiffness of the implant decreases from 100% to 25%, the differences in trabecular loading are extremely small. Both these implant material properties are very stiff in comparison to the underlying trabecular bone. However, as CoCr stiffness is decreased to 2.5% this yields a more homogenous stress distribution at the contact interfaces.

H. Gray A. Zavatsky L. Cristofolini D. Murray H.S. Gill

Finite element (FE) analysis is widely used to calculate stresses and strains within human bone in order to improve implant designs. Although validated FE models of the human femur have been created (Lengsfeld et al., 1998), no equivalent yet exists for the tibia. The aim of this study was to create such an FE model, both with and without the tibial component of a knee replacement, and to validate it against experimental Results: A set of reference axes was marked on a cleaned, fresh frozen cadaveric human tibia. Seventeen triaxial stacked strain rosettes were attached along the bone, which was then subjected to nine axial loading conditions, two four-point bending loading conditions, and a torsional loading condition using a materials testing machine (MTS 858). Deflections and strain readings were recorded. Axial loading was repeated after implantation of a knee replacement (medial tibial component, Biomet Oxford Unicompartmental Phase 3). The intact tibia was CT scanned (GE HiSpeed CT/i) and the images used to create a 3D FE mesh. The CT data was also used to map 600 transversely isotropic material properties (Rho, 1996) to individual elements. All experiments were simulated on the FE model. Measured principal strains and displacements were compared to their corresponding FE values using regression analysis.

Experimental results were repeatable (mean coefficients of variation for intact and implanted tibia, 5.3% and 3.9%). They correlated well with those of the FE analysis (R squared = 0.98, 0.97, 0.97, and 0.99 for axial (intact), axial (implanted), bending, torsional loading). For each of the load cases the intersects of the regression lines were small in comparison to the maximum measured strains (< 1.5%). While the model was more rigid than the bone under torsional loading (slope =0.92), the opposite was true for axial (slope = 1.14 (intact) 1.24 (implanted)) and bending (slope = 1.06) loads. This is probably due to a discrepancy in the material properties of the model.

S. Ostermeier C. Stukenborg-Colsman C. Hurschler H. Windhagen

INTRODUCTION The ability to evaluate the alignment of total knee arthroplasty using postoperative radiographs might be confounded by limb rotation. The aim of the presented study was therefore to measure the effect of limb rotation on postoperative radiographic assessment and to introduce a mathematical correction to calculate the true axial alignment in cases of a confounded radiograph.

METHODS A synthetic lower left extremity (Sawbones®, Inc,Vashon Island, WA) was used to create a total knee arthroplasty of the Interax I.S.A.® knee prosthesis system (Stryker, Limerick, Ireland). Laser guided measurement of the tibia showed a femoral valgus angle of 6.5° postoperatively. The model was fixed in an upright stand which positioned the limb in varying degrees of rotation. Four series of 10 antero-posterior (AP) radiographs were taken with the knee in full extension, with femoral limb rotation ranging from 20° external rotation to 20° internal rotation in respect to the x-ray beam, in 5° increments. After digitizing each radiograph, four observer independently measured the femoral valgus angle for each series of the long leg radiographs using a digital measurement software (MEDICAD®, Hectec, Altfraunhofen, Germany). Each observer was instructed to determine the femoral valgus angle following the software’s guidelines. In addition each observer measured the geometrical distances of the femoral component figured on the radiographic film. Using a student t-test, the effect of femoral limb rotation on the measured femoral valgus angle and a correlation between femoral rotation and femoral valgus angle was established. Then for each limb rotation the distances ratio was determined to calculate the limb rotation.

RESULTS Without an application of femoral rotation the femoral valgus angle was measured radiographically to be 6.5° (SD 0.4°). With external femoral rotation the measured femoral valgus angle linearly decreased to a minimum of 4.5° (SD 0.2°) at 20° femoral rotation. The linear regression (R2=0.94) calculated a 0.09° change of radiographically measured femoral valgus angle per femoral rotation angle. With the femoral rotation the radiographically measured ratio decreased linearly (R2=0.98) with further internal rotation.

DISCUSSION The results of the presented study suggest a significant influence of femoral rotation during radiographic evaluation of limb alignment after total knee arthroplasty. With further external femoral rotation the radiographically apparent femoral valgus angle decreases. As the apparent femoral valgus angle changes linearly, a calculation of the distances of the particular femoral component could be used to determine the real femoral valgus angle in cases of femoral limb rotation.

D. Nicoll D. Rowley

The aim of this study is to identify the incidence of mal-rotation of TKR components in a group of patients with unexplained knee pain identified from the University of Dundee joint replacement database and compare that group with a group of painless TKRs

38 of 45 NexGen LPS Total Knee Replacements identified with unexplained pain at a minimum of 1 year following surgery underwent CT scanning to determine rotational alignment. All patients had a Knee Society Pain score of 20 points or less and a mean Visual Analogue Pain Score of greater than 4.0. This group was compared with a control group of 26 TKRs all of which had never reported pain from 1 year post surgery.

In the painful group mean femoral component rotation was 2.2° of internal rotation (range 8.8°IR to 3.9°ER, sd 3.6, SEm 0.59) compared to 0.9°IR (range 6.9°IR to 6.8°ER, sd 3.39, SEm 0.67) in the painless group (p= 0.15). In the painful group 21.6% of femoral components were more than 6° internally rotated compared with 7.7% in the painless group however this was not statistically significant (p=0.18). No femoral components in either group were in excessive (over 8 degrees) ER.

Tibial component rotation was much more variable than femoral component rotation in both groups particularly in the painful group. Mean tibial component rotation was 4.1°IR (range 37.9°IR to 31.1°ER, sd 14.6, SEm 2.4) in the painful group compared to 2.2°ER (range 8.5°IR to 18.2°ER, sd 6.95, SEm 1.36) in the painless group (p=0.024). 15 tibial components (39.5%) were greater than 10° internally rotated in the painful group whilst no tibial components were more than 10° internally rotated in the pain free group (p< 0.001). In the painful group 7 tibial components (18.4%) were more than 10° externally rotated whilst 4 (15.4%) were in more than 10° ER in the painless group (p=1.00). Overall 22 tibial components (57.9%) were in more than 10° of malrotation in the painful group compared with 4 (15.4%) in the pain free group (p=0.05).

Mean rotational mismatch between femoral and tibial components was 1.9° tibial IR (range 39.7° tibial IR to 35.1° tibial ER, sd 16.1, SEm 2.7) in the painful group whilst in the painless group mean rotational mismatch was 3.1 degrees tibial ER (range 10.3° tibial IR to 22.1° tibial ER, sd 8.4, SEm 1.65). This difference was not significant (p=0.12). 16 TKRs (55.3%) had rotational mismatch of more than 10° in the painful group compared to 7 (26.9%) in the control group (p=0.02).

We conclude that rotational malalignment is frequent in painful total knee replacements and may be a major cause of pain after TKR. In particular tibial internal rotation is the most frequent alignment error in the painful TKR and appears to play a major role in the aetiology of pain after TKR.

R. Shariff M. Manickham M. McNicholas

Background: Osteoarthritic patients needing a TKA give pain as the major reason for being unable to exercise to lose weight. Weight gain in turn worsens the process of osteoarthritis, this feeds into the vicious cycle. Following a TKA, patients should ideally be able to exercise more and hence lose weight. We assessed this hypothesis in our prospective study by calculating BMI. BMI has been proven in previous studies to be a good reflection of body fat.

Materials and Methods: We prospectively followed up 94 patients in the knee arthroplasty clinic. Height, pre operative weight and post operative weight at 12 months were measured. All the peri-operative factors in all the patients were constant. We then calculated the pre and post operative BMI.

Results: Most of our patients at the 12 month follow up showed to have an increase in BMI. This difference was however not found to be statistically significant.

Conclusion: The result obtained in our study was contrary to previous studies which have shown significant change. We conclude that pre-operative pain alone is not a limiting factor in patient BMI changes peri-operatively.

T.G. Ryan B. Ohlson R. Adams

Introduction: Postoperative rehabilitation protocols following total knee replacement vary considerably among surgeons. Previous reports have shown the usefulness of music exercise videos for cardiovascular rehabilitation and general fitness. The authors created a music exercise video for use in the postoperative period following total knee replacement.

Methods: A prospective study was done whereby 45 patients undergoing 51 primary total knee replacements were randomized to a control (25) or video (26) group. All procedures were done by the senior author. All patients were evaluated at postoperative week 1,2,4,6, and 8 by a blinded examiner who generated Knee Society scores. Patients also completed a satisfaction questionnaire and the 8 week cost of rehabilitation was documented.

Results: Significant improvements were noted in patient’s assessment of understanding, confidence, and overall satisfaction when using the video (p< 0.05). Average return to usual activities was 34 days in the control and 14 days in the video group (p< 0.0001). Knee Society knee and function scores were improved for the video group and were statistically significant for the 6 and 8 week scores (p< 0.05). The combined Knee Society score at 6 weeks was 141 for the control group and 167 for the video group (p< 0.05). The therapy costs averaged US$2,602.00 in the control and US$287.00 in the video (p< 0.0001). No complications were reported while using the video.

Discussion: Use of the music video as a supplement to the rehabilitation program in the early postoperative period following total knee replacement is recommended due to improved patient satisfaction, earlier return to activities, and improved 6 and 8 week knee scores. These are achieved at a substantial cost savings which benefits both patients and society.

S. Tarabichi A. Tarabichi

Introduction: Morbidity and mortality are major concerns after simultaneous bilateral TKA. This paper reviews the results of patients who had simultaneous bilateral TKA (558 patients) and compares it to the results of single TKA (485 patients) carried out by the same surgeon in the same institution using same intra operative and post operative protocols.

Material and methods: 558 patients underwent simultaneous bilateral TKA while 485 underwent single TKA carried out by the same surgeon. The pre-op medical evaluation was carried out by a special multidisciplinary medical team. The decision to proceed with simultaneous TKA was made based on the clinical findings pre operatively. There were no additional special cares for the simultaneous group (central or arterial line) during surgery. Post op protocols were the same for both groups

Results: Blood transfusion was higher in the simultaneous knee surgeries (71%) as compared to (34 %) in a single knee group. We had 8 unscheduled ICU admission in the simultaneous group compared to 2 in the individual. Surprisingly DVT was less common in the simultaneous group. We had one death in the simultaneous group. The average knee score and average range of motion were the same in both groups.

Discussion and conclusion: Simultaneous bilateral TKA is safe. It is more economical and convenient, especially for patients who travel for the surgery. A special multidisciplinary task force is recommended to make the simultaneous knee surgery safe.

D.M. Rose W. Rahman H. Chan A.J. Trompeter S.H. Palmer

Purpose of study: To determine whether positioning the operated limb in flexion on a CPM machine reduces blood loss following uncemented total knee replacement. We also sought to determine whether limb arterial pressure, represented by ankle-brachial pressure index (ABPI), is affected by position of the limb.

Methods: We compared two groups of age and sex matched patients undergoing uncemented total knee replacement. The control group were treated in the postoperative period with the leg positioned flat in extension (48 patients). The CPM group were placed on a CPM machine at 90° of knee flexion for twelve hours immediately post-operatively (46 patients). Haemoglobin and haematocrit levels, blood transfusion requirement, length of hospital stay, range of motion and complications were compared.

In addition, we measured ankle and brachial pressures in a separate group of 39 patients with the limb in three different positions: flat with the knee in extension (ABPI 1), raised with the knee in extension (ABPI 2), and finally with the knee flexed to 90° (ABPI 3).

Results: The CPM group demonstrated a smaller drop in haemoglobin level (2.5 vs 3.1, p=0.013) and a reduced blood transfusion requirement (3 patients vs 14 patients, p < 0.05) in the post-operative period when compared to the control group. There was no significant difference in haematocrit drop, discharge range of motion, complications or length of hospital stay between the two groups.

ABPI measurements were calculated in the standard fashion, the mean ABPI in each limb position being 1.17 (ABPI 1), 0.87 (ABPI 2) and 0.83 (ABPI 3) respectively.

Conclusions: Short-term use of a CPM machine in the post-operative period reduces blood loss and appears safe following uncemented total knee replacement. We found limb arterial pressure to be reduced to the greatest extent with the limb in a position of 90° flexion at the knee, which may account for the reduction in blood loss seen in the CPM group.

S. Bridgman G. Walley D. Clement D. Griffiths G. Mackenzie N. Maffulli

Introduction: Fifty thousand knee replacements are performed annually in the UK at an estimated cost of £150 million. However, there is uncertainty as to the best surgical approach to the knee joint for knee arthroplasty. We undertook a randomised controlled trial to compare a standard medial parapatellar arthrotomy with sub-vastus arthrotomy for patients undergoing primary total knee arthroplasty in terms of short and long term knee function.

Methods: Two-hundred and thirty-one patients undergoing primary total knee arthroplasty during 2001–2003 were recruited into the study. Patients were randomised into subvastus (116) or medial parapatellar (115) approaches to knee arthroplasty. The primary outcome measures were the American Knee Society and WOMAC Scores. The secondary outcome measures were patient based measures of EuroQol and SF-36. All outcomes were measured pre-operatively, 1, 6, 12 and 52 weeks post-operatively. We also looked at a pain diary, analgesia diary, ease of surgical exposure, and complications.

Results: Pain as measured by WOMAC was significantly less in the subvastus group but only at 52 weeks. The Knee Society Score showed some early benefit at one week to the subvastus group. There was no difference between the two groups in relation to the knee function score, EuroQol, SF-36, pain diary, analgesia usage and length of hospital stay.

Conclusion: There is some benefit to patients receiving sub-vastus arthrotomy relative to medial para-patellar. Although the results show some statistical significance in using the sub-vastus approach the clinical importance of these findings and the costs of the various procedures involved remain to be ascertained.

Y. ISHII H. Noguchi Y. Matsuda

In this prospectively randomized study, we compared the changes in the range of motion (ROM) in posterior cruciate ligament-retaining (PCLR) (n=50) and -sacrificing (PCLS) (n=50) total knee arthroplasties during the perioperative period. The median ROM in PCLR prostheses was 122.5° preoperatively, 120.0° intraoperatively, and 100.0° at discharge, and 115.0°, 120.0°, and 95.0°, respectively, in PCLS. The designs did not differ statistically in each period (p> 0.05). Both designs showed significant correlations between the preoperative and intraoperative ROM, and between the preoperative and discharge ROM. Only the PCLS showed a significant correlation between the intraoperative and discharge ROM. Since the PCL tenses with flexion, the degree of preoperative degeneration, intraoperative recession, and postoperative tension of the PCL may have played a major role in the results. The PCLS design has an advantage in rehabilitation planning because of the predictable changes in the ROM during the perioperative period, although the acquired average ROM at discharge did not differ statistically.

M. Hildebrand N. Gutteck D. Wohlrab W. Hein

Introduction: The aim of the study is to evaluate different operation techniques after total knee arthroplasty (TKA). Functional outcome as well as objective results in activity (activity monitor) after minimal invasive TKA was compared with functional outcomes after a standard midvastus approach.

Purpose: The primary purpose of the present study was to determine the difference between two approaches in surgery of total knee arthroplasty. Is there a difference in outcome between a standard and a minimal invasive surgery because of less muscle damage and soft tissue stress?

Material and methods: The study includes two groups with 20 patients each (MIS group versus standard group) The patients are investigated at six different times: 1 day preoperatively as well as on 1., 3., 7. day postoperatively as well as 6 and 12 weeks after surgery. We used the AMP 331 (Dynastream Innovations, Inc., Cochrane, AB) a new ankle-mounted activity monitor. Step count, distance travelled, walking speed, step length, cadence and energy expenditure were measured. 1, 6 and 12 weeks postoperatively patients got the device for 5 days.

Results: The average age in the standard group was 66.4 years and for the MIS group, 66,8. The MIS group has been shown a sig. higher KSS Score versus standard group in all follow up visits. Standard group has shown a slight higher blood loss and higher values of muscle specific lab parameter (Creatininkinase and Myoglobin). The Activity Score was better in the MIS group in comparison to the standard group. These results also mirrored the data from the activity monitor (AMP 331, Dynastream Innovations, Inc., Cochrane, AB). The average walking speed at 1, 6 and 12 weeks was sig. (p< 0.05) better than in the standard group. Same trend we have seen in cadence, step length and steps per day.

Conclusion: This study shows that patient who underwent minimal invasive surgery in knee arthroplasty have an better early outcome after surgery in activity and function because of saving muscle structure and minimise soft tissue stress.

J.R. Murray M. Sherlock N. Hogan C. Servant S. Palmer E. Parish M.J. Cross

Background: The purpose of this study was to assess the anterior femoral cortical line (AFCL) as an additional anatomical landmark for determining intraoperative femoral component rotation in total knee arthroplasty. The AFCL was compared with the Epicondylar axis, the anteroposterior (AP) axis (Whiteside’s line), and the posterior condylar axis. Dry bone, cadaver, MRI and intra-operative measurements were compared.

Methods: Fifty dry bone femora, and 16 wet cadaveric specimens were assessed to identify the AFCL and this was compared against the 3 reference axes discussed above. Photographs were taken of the specimens with K-wires/marker pins secured to the reference axes and then a digital on-screen goniometer was used to determine the mean angular variations with respect to the Epipcondylar axis.

In the clinical trial, 58 consecutive patients undergoing total knee arthroplasty were included. After a routine exposure the AP axis was marked on each distal femur. The AFCL was then identified and the anterior femoral cortical cut was made parallel to this line. The angle between this cortical cut and the perpendicular to the AP axis was measured using a sterile goniometer.

In the MRI study, 50 axial knee images were assessed and the most appropriate slice/s determined in order to identify the AFCL and the other 3 reference axes and then their relationship was measured by an on-screen goniometer.

Results: In the cadaveric study the AFCL was a mean 1° externally rotated to the epicondylar axis (SD = 5°), White-side’s line was 1° externally rotated (SD = 4°) and the posterior condylar axis was 1° internally rotated (SD = 2°)

By MRI and with respect to the epicondylar axis, the AFCL was a mean 5° externally rotated (SD= 3), White-side’s Line was 1° externally rotated (SD = 2) and the posterior condylar axis was 3° internally rotated (SD = 2).

In the clinical study in 8 patients it was impossible to draw the AP axis because of dysplasia or destruction of the trochlea by osteoarthrosis. In the remainder the mean difference between the anterior femoral cortical line and Whiteside’s AP axis was 4.1 degrees internally rotated (SD = 3.8°). The lateral release rate for this cohort was 4%.

Conclusion: The anterior femoral cortical line provides an additional reference point, completing the ‘compass points’ around the knee. It has been shown in this study to be reliable in the laboratory, on MRI and in a clinical setting for assessing rotation of the femoral component. It may prove particularly useful when one or all of the other reference axes are disturbed such as in revision TKR, lateral condylar hypoplasia or where there has been previous epicondylar trauma.


Introduction: A successful total knee replacement (TKR) relies upon effective soft tissue management. Historically, soft tissue balancing has been difficult to assess and quantify intraoperatively. Computer navigation permits us to accurately assess kinematics during surgery. In a previous study we performed a series of varus and valgus stress measurements in extension to devise an algorithm for soft tissue management. In this study we evaluate the effectiveness of this algorithm.

Methods: This prospective study used the Orthopilot® CT-free navigation system during TKR for 57 patients with end-stage arthritis. We collected intraoperative kinematic data for 42 varus knees. Pre- and post-operatively, a varus and valgus stress was applied at maximum extension, recording the mechanical femorotibial (MFT) angle. There were no patellar resurfacings. The following medial releases were performed based upon the kinematics and the algorithm below:

No release–MFT angle not less than −12° with varus stress, greater than 2° with valgus stress, and/or if extension deficit was not greater than 5°.

Moderate release–MFT angle less than −12° with varus stress, between −5° and 2° with valgus stress, and/or extension deficit not greater than 5°.

Proximal release–MFT angle less than −12° with varus stress, less than −5° with valgus stress, and/or extension deficit greater than 5°.

Results: Pre-operatively, the mean MFT angle was −9.6°varus (−3° to −22°) with varus stress and −0.8°varus (4° to −11°) with valgus stress. Post-operatively, the mean MFT angle was −3.5° varus (0° to −5°) with varus stress, and 2.1° valgus (4° to −1°) with valgus stress.

Using regressional analysis, there was a strong linear correlation between both varus (r=0.871, p< 0.0001) and valgus (r=0.894, p< 0.0001) stresses and the MFT angle.

Post-operatively, the mean MFT angle was maintained within a narrow range (0° to −5° with varus stress, 4° to −1° with valgus stress), with no outliers. There were no extension deficits.

Conclusions: Using computer navigation a quantifiable soft tissue management system was introduced. We evaluated this algorithm, and obtained reproducible results within a narrow range and no outliers. This algorithm may provide an effective soft tissue management plan in TKR.

D. Howcroft M. Fehily C. Peck A. Fox B. Dillon D. Johnson

Templating of preoperative radiographs is routinely recommended prior to knee arthroplasty. We performed this study to assess the reproducibility and accuracy of the templates for three commonly used knee implants (PFC, Kinemax, Scorpio). Six lower limb surgeons templated 10 patients for each of the three designs. The inter and intra-observer reliability and accuracy was calculated. There was marked variation in the reliability of the templating with the tibial insert scoring better than the femoral and the Kinemax being the most reproducible of the three. In general, the intra-observer scores (κ= 0.57–0.81) were better than the inter-observer ones (κ= 0.21–0.60). The Scorpio was the most accurately templated of the three implants, with the percentage correlating with what was actually implanted ranging from 55–62% for the femur and 72–75% for the tibia, with no templated sizes more than 1 size different from the actual implant. The other implants ranged from 38–42% for the femur and 53–58% for the tibia with both having up to 3% more than 1 size difference from the actual implant. We believe that the use of templating in total knee arthroplasty should be interpreted with caution and we urge the development of more accurate prosthesis sizing techniques.

A.J. Schuster A. von Roll T. Wyss

Aims : This prospective study investigated outcomes from TKA using the ligament balancing technique to implant a PCL-retaining knee prosthesis (balanSys knee system). In addition we wanted to know if we can achieve stability in these knees and if there is a difference between mobile and fixed bearing prosthesis designs?

Methods: Between March 2001 and Mai 2005 143 patients (17 bilateral; n=160) with osteoarthritis received the balanSys knee system with either a fixed or mobile polyethylene bearing. Objective assessments of the implant used Knee Society score (KSS) with the knee and functional score. Anterior-posterior translation was measured with the Rolimeter (Aircast) in 25° (Lachman) (mean of 3) and 90° of knee flexion (mean of 3), intraoperatively under anaesthesia and at follow up time. Subjective assessments used Visual Analogue Scale (VAS) data for pain, and patient satisfaction.

Results: The study population at follow up time (mean 4 years) contained 112 patients (31 males; 81 females) with 126 knee implants out of 160. Of these 126, 93 had fixed and 33 mobile bearings. Mean age at surgery was 70.6 years. The Rolimeter measurements for ap-translation showed an increase of stability from 8.3 preop to 4.6 mm at FU in 25° of flexion and 6.3 to 4.9 in 90° of flexion. The increase of stability for mobile bearings (7.8 to 5.8/6.1 to 6.0) is smaller than for fixed bearings (8.4 to 5.8/6.9 to 4.5). The t-test shows a clear cut significance Pr > [t] = 0.0038, the difference of the paired difference amounts to 1.4 mm. The t-test shows significant differences for both angles (25°/90°) Pr > [t] < 0.001. Mobile bearings have a higher laxity in ap direction compared to fixed bearings. ROM was similar for both genders (mean 118°). According to VAS, mean scores for pain and satisfaction were 1.5 (best 0) and 8.5 (best 10), respectively. The KSS (mean score 168; SD 31.1) was similar for both, fixed and mobile bearings. In 25° of flexion the subgroup of ‘tight’ knees (1–3.5 mm ap translation) and in 90° the subgroup of ‘loose’ knees (< 5.5 mm) performed best, with highest knee scores.

Conclusions: The TKA’s performed with a PCL-retaining prosthesis and a soft tissue oriented, ligament balancing, surgical technique were associated with good outcome (KSS mean score 168), a good range of motion (118°), good stability and with no significant differences between mobile bearing or fixed bearing implants at follow up (4 years). In addition patients reported little pain (1.5) and were very satisfied (8.5) with the outcome. Interesting was the fact that in 25° of flexion the subgroup of tight knees (1–3.5mm) and in 90° the subgroup of loose knees (< 5.5 mm) performed best, with highest knee scores.

A. Martin M.B. Sheinkop A. von Strempel

Aims: Because of the limitation of exposure inherent in minimally invasive surgical techniques for total knee replacement surgery, there is a significant risk of malalignment, malrotation, femoral notching and failure of soft tissue balance.

Methods: In this randomized study 50 patients with osteoarthritis of the knee, underwent TKR through a minimally invasive exposure using a navigation system; while a control group of 50 patients underwent the same surgery without navigation.

A subvastus approach was used with a less than 10 cm incision. Femoral component alignment is established with an intramedullary, and the tibial component, with an extramedullary alignment guide. The navigation system was used for fine adjustment and verification of cutting block position. The navigation system used for the study was the VectorVision® CT-Free Knee 1.5.1.

Results: The accuracy of prosthetic components positioning was significantly higher in the navigation group. The navigation system offered an objective analysis of medial and lateral ligament tension in full extension and 90 ° of flexion. In 8 cases navigation avoided femoral notching. No navigation related complications were registered. The additional surgery time for computer-assisted TKR was a mean 21 minutes. The nonnavigated implantation technique reached perfect component positioning in 62 % of the TKR.

Conclusion: Computer-assisted TKR results in predictable and accurate alignment, avoidance of femoral notching, avoidance of malrotation and appropriate balance of the soft tissue. Performing minimally invasive TKR without navigation has a higher risk of increased rate of unsatisfactory outcomes with shorter prosthetic survivorship when compared to the use of navigation.

S. yousufuddin D. chesney M. van der linden R. nutton

Objective: To evaluate the impact of soft tissue release on range of movement following total knee replacement.

Methods: Sixty four patients underwent PFC sigma total knee replacement through a medial arthrotomy. Range of active movement was measured preoperatively, and maximal flexion was measured after implantation, using the drop test while the patient was under anaesthetic. Soft tissue release was graded from 1 to 5, depending on the structures released.

Range of movement was correlated with extent of soft tissue release, to see if release had any impact on increase in range of movement.

Results: All patients had an improvement in range of movement following surgery. Post operative range of movement correlated strongly with preoperative ROM.

Patients requiring extensive releases tended to have less preoperative ROM, but the gain was independent of medial release. Those requiring extensive posterior release had poorer preoperative movement, and significantly less improvement.

In those requiring an extensive medial release, a posterior release improved gain in ROM.

Conclusion: Postoperative ROM following TKR is independent of extent of medial release. In patients requiring extensive medial release, a posterior release improves gain in movement.

S.A. Banks K.H. Mitchell M.K. Harman C.J. Leslie W.A. Hodge

There is interest to provide total knee arthroplasty (TKA) patients large ranges of functional knee flexion. Factors contributing to flexion include a posterior femoral position on the tibia, posterior condylar offset, and posterior tibial slope. These factors can be incorporated into implant designs and surgical techniques. It is useful to assess the robustness of the resulting design, that is, the consistency of kinematic or functional results when patient and surgical factors vary widely. This study evaluates in vivo flexion performance of a single implant design in patients whose posterior cruciate ligament (PCL) was either retained or sacrificed.

28 knees in 20 patients were imaged using fluoroscopy during maximum flexion kneeling and lunge activities. 20 knees (12 patients) received TKA with the PCL retained by a bone block (PCL+ group). Eight knees (7 patients) received TKA with complete PCL resection (PCL- group). All knees received a fixed-bearing TKA (3D Knee, Encore Medical, Austin, TX) with an asymmetric tibial bearing having a sagittally curved medial compartment and a lateral compartment fully congruous with the lateral condyle in extension (approximating anterior cruciate ligament substitution). Three-dimensional knee kinematics were determined using model-based shape registration techniques.

For the kneeling activity, mean implant flexion was 124°±11° for PCL+ knees and 121°±17° for PCL- knees (p> 0.05), mean tibial internal rotation was 10°±4° for PCL+ knees and 9°±3° for PCL- knees (p> 0.05) and tibial valgus was −1°±1° for PCL+ knees and 2°±4° for PCL- knees (p=0.003). Medial contact location averaged −2±4mm and for PCL+ knees and −1±2mm for PCL- knees (p> 0.05). Lateral contact location averaged −10±4mm for PCL+ knees and −7±1mm for PCL- knees (p> 0.05). For the lunge activity, mean implant flexion was 120°±11° for PCL+ knees and 121°±21° for PCL- knees (p> 0.05), mean tibial internal rotation was 11°±4° for PCL+ knees and 8°±3° for PCL- knees (p> 0.05) and tibial valgus was −1°±1° for PCL+ knees and 2°±2° for PCL- knees (p=0.0002). Medial contact location averaged 0±4mm for PCL+ knees and −4±3mm for PCL- knees (p=0.04). Lateral contact location averaged −8±4mm for PCL+ knees and −9±4mm for PCL- knees (p> 0.05).

There was no difference in implant flexion between PCL retaining and sacrificing TKA. Both groups had knees with more than 145° implant flexion (~155° skeletal flexion). There were no significant differences in tibial rotation or lateral condylar contact locations. There were differences in tibial valgus for both activities. PCL- knees exhibited a tendency for the medial compartment to ‘book open’ with flexion beyond 130°, consistent with loss of PCL function. Based on this small cohort comparison, it appears that robust flexion performance and knee kinematics can be obtained with a fixed-bearing TKA design.

S. Hakkalamani A. Acharya R. Finley N.J. Donnachie

Introduction: Restoring normal mechanical axis is one of the