Adolescent idiopathic scoliosis is a three-dimensional deformity of the spine, affecting 1–3% of the population.

Most cases are treated conservatively. Curves exceeding 45° in the thoracic spine and 40° in the lumbar spine may require correction and fusion surgery, to limit the progression of the curve and prevent restrictive pulmonary insufficiency (curves above 70°). When fusion is required, it may be performed either by posterior or anterior approaches. Posterior is useful for thoracic (Lenke I) curves, notably to correct the thoracic hypokyphosis frequently observed in AIS. Anterior approaches by thoraco-lombotomies allow an effective correction of thoraco-lumbar and lumbar curves (Lenke V and VI), with fewer levels fused than with posterior approaches. However, the approach requires diaphragm splitting and one may be concerned about the long-term pulmonary consequences. The literature provides conflicting insight regarding the consequences of the approach in anterior scoliosis correction, the interpretation of the results being difficult knowing that the correction of the scoliosis itself may improve pulmonary function.

This is a retrospective observational study done at a Tertiary Institution. The HRQOL scores have been collected as a prospective cohort. Clinical and radiographic data was collected from patients charts and analysed by two senior surgeons

A cohort of 64 patients were operated in the given time period. 50 patients met the inclusion criteria. No major complications were reported. The Union rate was 100% and no post operative complications were noted. Pre and post SRS scores improved in all patients.

The Anterior approach for Lenke V AIS gives great surgical exposure and allows for excellent correction of Cobb angle with minimal risk to the patient.

Rates of prosthetic joint infection in megaprostheses are high. The application of silver ion coating to implants serves as a deterrent to infection and biofilm formation.

A retrospective review was performed of all silver-coated MUTARS endoprosthetic reconstructions (SC-EPR) by a single Orthopaedic Oncology Surgeon. We examined the rate of component revision due to infection and the rate of infection successfully treated with antibiotic therapy. We reviewed overall revision rates, sub-categorised into the Henderson groupings for endoprosthesis modes of failure (Type 1 soft tissue failure, Type 2 aseptic loosening, Type 3 Structural failure, Type 4 Infection, Type 5 tumour progression).

283 silver-coated MUTARS endoprosthetic reconstructions were performed for 229 patients from October 2012 to July 2022. The average age at time of surgery was 58.9 years and 53% of our cohort were males. 154 (71.3%) patients underwent SC-EPR for oncological reconstruction and 32 (14.8%) for reconstruction for bone loss following prosthetic joint infection(s). Proximal femur SC-EPR (82) and distal femur (90) were the most common procedures. This cohort had an overall revision rate of 21.2% (60/283 cases). Component revisions were most commonly due to Type 4 infection (19 cases), Type 2 aseptic loosening/culture negative disease (15 cases), and Type 1 dislocation/soft tissue (12 cases).

Component revision rate for infection was 6.7% (19 cases). 15 underwent exchange of implants and 4 underwent transfemoral amputation due to recalcitrant infection and failure of soft tissue coverage. This equates to a limb salvage rate of 98.3%. The most common causative organisms remain staphylococcus species (47%) and polymicrobial infections (40%).

We expand on the existing literature advocating for the use of silver-coated endoprosthetic reconstructions. We provide insights from the vast experience of a single surgeon when addressing patients with oncological and bone loss-related complex reconstruction problems.

INTRODUCTION

The benefits of combining enhanced recovery after surgery (ERAS) interventions with an outpatient THA/TKA program are uncertain. The primary objective was to compare adverse event rate and secondly to compare pain management, functional recovery, PROMs and patients' satisfaction.

Aims

We aimed to address the question on whether there is a place for shoulder stabilization surgery in patients who had voluntary posterior instability starting in childhood and adolescence, and later becoming involuntary and uncontrollable.

Purpose and Background

Both overall spine shape and the size and shape of individual vertebrae undergo rapid growth and development during early childhood. Motor development milestones such as age of walking influence spine development, with delayed ambulation linked with spinal conditions including spondylolysis. However, it is unclear whether associations between motor development and spine morphology persist into older age. Therefore, these associations were examined using data from the MRC National Survey of Health and Development, a large nationally-representative British cohort, followed up since birth in 1946.

The World Health Organisation (WHO) Surgical Safety checklist is an evidence-based tool shown to reduce surgery-related morbidity and mortality. Despite audits showing 96% checklist compliance, our hospital had 3 surgical never events in 10 months, 2 of which were in orthopaedics. By March 2018, the authors aimed to achieve 100% compliance with all 5 sections of the WHO Five Steps to Safer Surgery bundle for all surgical patients. Additionally, the authors aimed to assess the impact of the quality of bundle delivery on preventable errors related to human factors. Quantitative assessment involved direct observations of compliance in theatres. Qualitative data in the form of rich, descriptive observations of events and discussions held during checklist delivery was analysed thematically. Interventions included trust-wide policy changes, awareness sessions, introduction of briefing and debrief proformas and documented prosthesis checks. For elective surgeries, checklist compliance increased to 100% in 4 of 5 sections of the bundle. The incidence of reported preventable critical incidents decreased from 6.7% to 2.4%. A chi-squared test of independence demonstrated a significant relationship between the implementation of changes and completion of the checklist, X2 (1, N = 1019) = 25.69, p < 0.0001. Thematic analysis identified leadership, accountability, engagement, empowerment, communication, and teamwork as factors promoting effective checklist use. Our findings highlight the benefits of a qualitative approach to auditing checklists. Exploring the role of human factors and promoting staff awareness and engagement improves checklist compliance and enhances its effectiveness in reducing surgery-related adverse outcomes.

Aims

Little is known about the effect of haemorrhagic shock and resuscitation on fracture healing. This study used a rabbit model with a femoral osteotomy and fixation to examine this relationship.

Purpose

To investigate associations between sagittal thoracolumbar spine shape with sex and measures of adiposity throughout adulthood.

Aim

Our hospital is a referral center for Bone and Joint Infection (BJI) with a 15-bed orthopedic unit. Patients benefit from a multidisciplinary team management (surgeons, anesthetists, infectious disease physicians, microbiologists, dietician etc.). Computerized drug prescriptions are performed by anesthetists, surgical residents, surgeons and infectious disease physicians. Since 2015, a pharmacist has been included in ward rounds and in weekly multidisciplinary consultative meetings, where antibiotic treatment strategies are decided for hospitalized patients. This work aimed to assess the impact of a pharmacist in this unit to limit prescription errors.

Adipose tissue is an attractive source of mesenchymal stem cells (MSCs) as it is largely dispensable and readily accessible through minimally invasive procedures such as lipoaspiration. Until recently MSCs could only be isolated in a process involving ex-vivo culture. Pericytes (CD45−, CD146+, and CD34−) and adventitial cells (CD45−, CD146−, CD34+) represent two populations of MSCs (collectively termed perivascular stem cells or PSCs) that can be prospectively purified using fluorescence activated cell sorting (FACS). We performed FACS on lipoaspirate samples from n=129 donors to determine the frequency and yield of PSCs and to establish patient and processing factors that influence yield.

The mean number of stromal vascular fraction (SVF) cells from 100ml of lipoaspirate was 37.8×106. Within the SVF, mean cell viability was 82%, with 31.6% of cells being heamatopoietic (CD45+). Adventitial cells and pericytes represented 31.6% and 7.9% of SVF cells respectively. As such, 200ml of lipoaspirate would theoretically yield 24.5 million MSCs –a sufficient number to enable point-of-care delivery for use in several orthopaedic applications. The yield and prevalence of PSCs were minimally affected by donor age, sex and BMI. Storing lipoaspirate samples for up to 72 hours prior to processing had no significant deleterious effects on MSC yield or viability.

Our study confirms that pure populations of MSC-precursors (PSCs) can be prospectively isolated from adipose tissue, in sufficient quantities to negate the necessity for culture expansion while widening possible applications to include trauma, where a time delay between extraction and implantation excludes their use.

There is a high rate of mortality in elderly patients who sustain a fracture of the hip. We aimed to determine the rate of preventable mortality and errors during the management of these patients. A 12 month prospective study was performed on patients aged > 65 years who had sustained a fracture of the hip. This was conducted at a Level 1 Trauma Centre with no orthogeriatric service. A multidisciplinary review of the medical records by four specialists was performed to analyse errors of management and elements of preventable mortality. During 2011, there were 437 patients aged > 65 years admitted with a fracture of the hip (85 years (66 to 99)) and 20 died while in hospital (86.3 years (67 to 96)). A total of 152 errors were identified in the 80 individual reviews of the 20 deaths. A total of 99 errors (65%) were thought to have at least a moderate effect on death; 45 reviews considering death (57%) were thought to have potentially been preventable. Agreement between the panel of reviewers on the preventability of death was fair. A larger-scale assessment of preventable mortality in elderly patients who sustain a fracture of the hip is required. Multidisciplinary review panels could be considered as part of the quality assurance process in the management of these patients.

Cite this article: Bone Joint J 2014;96-B:1178–84.

Objectives

The goals of this study were: 1) to determine if high-fat diet (HFD) feeding in female mice would negatively impact biomechanical and histologic consequences on the Achilles tendon and quadriceps muscle; and 2) to investigate whether exercise and branched-chain amino acid (BCAA) supplementation would affect these parameters or attenuate any negative consequences resulting from HFD consumption.

International and national predictions from the late 1990s warned of alarming increases in hip fracture incidence due to an ageing population globally. Our study aimed to describe contemporary, population-based longitudinal trends in outcomes and epidemiology of hip fracture patients in a tertiary referral trauma centre.

A retrospective review was performed of all patients aged 65 years and over with a diagnosis of fractured neck of femur (AO classification 31 group A and B) admitted to the John Hunter Hospital, Newcastle, New South Wales between 1st January 2002 and 30th December 2009. Datawas collated and cross referenced from several databases (Prospective Long Bone Fracture Database, Operating Theatre Database and the Hospital Coding Unit). Mortality data was obtained via linkage with the Cardiac and Stroke Outcomes Unit, Planning and Performance, Division of Population Health. Main outcome measures were 30-day mortality, in-hospital mortality, length of stay.

The JHH admitted (427 ± 20/year, range: 391–455) patients with hip fractures over the 9 year study period. The number of admissions per year increased over the study period (p = 0.002), with no change in the age-standardised incidence (p = 0.1). The average age (83.5 ± 0.2) and average percentage female (73.7%) did not change. There was an overall trend to decreased 30-day mortality from 12.4% in 2002 to 7% in 2009 (p = 0.05). The factors that were associated with increased mortality were age (p < 0.0001), male gender (p = 0.0004), time to operating theatre (p = 0.0428) and length of stay (p < 0.0001).

In accordance with national and international projections on increased incidence of geriatric hip fractures, the incidence of fractured neck of femur in our institution increased from 2002–2009, reflecting our ageing population. 30-day mortality improved and longer length of stay corresponded with increased 30-day mortality.

Geriatric hip fracture patients have a 14-fold higher 30-day mortality than their age matched peers. Up to 50% of these patients receive blood transfusion perioperatively. Both restrictive and liberal transfusion policies are controversial in this population. Aim: The longitudinal description of transfusion practice in geriatric hip fracture patients in a major trauma centre.

An 8-year (2002–2009) retrospective study was performed on patients over the age of 65 undergoing hip fracture fixation. Yearly transfusion rate; the influence of transfusion on 30-day, 90-day and 1-year mortality and length of stay (LOS) was investigated. On admission haemoglobin (Hb), pre-transfusion Hb and post-transfusion Hb and their effect on transfusion requirement and mortality was also reviewed. The yearly changes in on-admission and pre-transfusion Hb were also examined. The influence of comorbidities, timing, procedure performed and operation duration on transfusion requirement and mortality was also studied. From the 3412 patients, 35% (1195) received transfusion during their hospital stay. There was no change in age, gender and co-morbidities during the study. Thirty-day mortality improved from 12.4% in 2002 to 7% in 2009. The transfusion rate showed a gradual decrease from the highest of 48.3% (2003) to 22.9% (2009) (Pearson correlation - R2 = −0.707, p=0.05). There was no change during the study period in on-admission and pre-transfusion Hb. The mortality for non-transfused and transfused patients was [9.6% vs. 10.3 % (30-day)], [17.2% vs. 18.4%(90-day)] and [27% vs. 30.5%(1-year), p=0.031]. LOS was 11±9 for non-transfused patients and 13±10 (p<0.001) for transfused patients. Patients with more comorbidities experienced a higher transfusion rate, (0 – 31%, 1 – 38%, 2 – 46%, 3 – 57%), (Pearson Chi-squared, p<0.001). The need for transfusion by different procedures in decreasing order was 47.6% intramedullary device, 44.0% DHS, 25.2% cemented hemiarthroplasty, 23.6% Austin-Moore, and 5.5% cannulated screws. The length of the operation increases the chance of transfusion (<1hrs, – 33%, 1–2hrs – 35%, 2–3hrs – 41%, >3 hours – 65%), (Pearson Chi-squared, p=0.010). Preoperative waiting time had no influence on transfusion frequency (<24hrs – 36%, 24–48hrs – 34%, 48–96hrs – 36%, >96hrs – 33%), (Pearson Chi-squared, p=0.823).

The percentage of transfused geriatric hip fracture patients halved during the eight-year period without changes in demographics and co-morbidities. Perioperative transfusion of hip fracture patients is associated with higher 1-year mortality and increased LOS. A more restrictive transfusion practice has been safe and may be a factor in the improved 30-day mortality.

PURPOSE

We performed an anatomical study to clarify humeral insertions of coracohumeral ligament (CHL) and superior glenohumeral ligament (SGHL) and their relationship with subscapularis tendon. The purpose of our study was to explain the « Comma Sign » observed in retracted subscapularis tears treated by arthroscopy.

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 the 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.

Purpose of the study: Different metatarsal osteotomies performed via a percutaneous approach can be used to correct hallux valgus. The purpose of this work was to analyse the clinical and radiographic results of percutaneous treatment of hallux valgus using a distal wedge osteotomy of the metatarsal.

Material and methods: This was a consecutive prospective series of 125 cases of hallux valgus treated by the same surgical technique, distal wedge osteotomy of the metatarsal without fixation. Percutaneous lateral arthrolysis and percutaneous varus correction of the first phalanx were associated. The AOFAS function score for the forefoot was determined preoperatively and at last follow-up. Time to normal shoe wearing and to resumption of occupational activities were also noted. Angle correction was determined on the anteroposterior weight-bearing image. All patients were reviewed at mean 20 months (range 12–40).

Results: The AOFAS forefoot function score was 46/100 preoperatively and 87/100 at last follow-up. Mean motion of the metatarsophalangeal joint was 95 preoperatively and 80 postoperatively. Mean metatarsophalangeal valgus was 30 preoperatively and 12 at last follow-up. The mean intermetatarsal angle improved from 13 to 8 and the orientation of the joint surface of the first metatarsal (DMAA) improved from 11 to 7. The metatarsophalangeal joint of the first ray was congruent in 45% of the feet preoperatively and in 88% postoperatively. Mean time to wearing normal shoes was seven weeks for the treatment of hallux valgus alone and three months for surgery of the first ray and lateral rays.

Discussion: Percutaneous treatment of mild to moderate hallux valgus by distal wedge osteotomy of the metatarsal enables good clinical and radiographic improvement. The surgical technique requires experience with percutaneous surgery of the forefoot to avoid the main complications: secondary displacement in elevates and excessive shortening of the first metatarsal. This technique restores metatarsophalangeal congruence of the first ray compared with Isham-Reverdin osteotomy.

Statement of Purpose: Hard-on-hard bearing surfaces are finding increasing application in total hip replacements for wear reduction. Polycrystalline Diamond Compacts (PDCs) offer several potential advantages, including ultimate hardness, reduced metal ion release compared to metal-on-metal (MoM) articulations and increased strength/ toughness compared to ceramic-on-ceramic (CoC). This study investigates in-vitro wear and friction for a 28mm diamond-on-diamond (DoD) system under normal walking gait and also with distraction.

Methods: Six sets of 28mm PDC femoral heads and 28/41mm PDC acetabular liners (Dimicron, Utah) were tested on a hip simulator (AMTI, Boston). Radial clearances were 18–42 microns. Specimens were mounted anatomically with the cups superior and mounted at 45 degrees. All stations were lubricated with 37oC bovine serum diluted to 17g/l protein concentration. Components were subjected to a 3kN walking cycle (ISO14242-1) for 5 million cycles (MC). This was followed by 2MC of distraction testing with a reduced swing-phase load of 120N, an applied side force of 129N and with the abduction motion disabled. This produced approximately 0.5–0.7mm of horizontal displacement of the center of the head. The lubricant was changed and the components cleaned, dried and weighed at 0.5MC intervals.

Results: All heads and liners gained weight during each portion of the test. Potential mechanisms (still under investigation) include protein adsorption and hydration of metallic phases within the diamond compact. The weight gains were found to be somewhat reversible after drying in vacuum for extended periods (60–90 hours). However, the standard 1 hour drying cycle used for weight measurements during the test was found to be inadequate. Therefore, only the “dry weights” measured after 64–92 hours of vacuum drying at the beginning and end of each test portion were used to compute wear rates.

Overall wear rates for heads and liners for the 5MC of normal gait and the 2MC of distraction testing and for the whole 7MC. 95% confidence intervals are plotted for each set of six heads and liners. Weight changes were converted to volumetric wear using a density of 3,800kgm-3. Even after extended drying, the liners all showed small weight gains. The heads apparently wore slightly during the normal walking cycle but gained weight during the distraction cycle. Overall, the heads showed a small wear rate of 0.17±0.09mm3/MC and the liners showed a small ‘negative’ wear rate of −0.11±0.07mm3/MC. Due to the uncertainties involved in the drying procedure, it is concluded that DoD wear rates were unmeasurably low for this test. Distraction is known to increase wear rates for CoC systems [1] and might reasonably be expected to have a similar effect for DoD, due to the high elastic modulus of diamond.

However, the 2MC of distraction testing produced only small weight gains. The heads showed no evidence of ‘stripe wear’ as reported for CoC systems.

Conclusions: DoD wear rates were found to be unmeasurably low for an anatomical hip simulator test with and without distraction. Friction factors for DoD were slightly lower than for metal-on-UHMWPE.

A prospective study of displaced femoral neck fractures was conducted, using the Corail® stem, a non cemented HA-coated device, provided with a bipolar head. 293 consecutive patients were included. Our reasons to shift to an uncemented implant were:

the existence of intraoperative deaths during cementation;

Follow-up was extended up to 5 years, unless the patient died before. 7 patients were lost from FU. Function was assessed every year using various clinical scores (Parker’s mobility score, Qureshi’s mental status, Jensen’s autonomy index,). An X-Ray was obtained at each visit when possible, with a special insistence at completion of the follow up (136 out of the 144 still alive patients).

Intraoperatively, 11 isolated calcar cracks and 1 fracture of the major trochanter were seen. In three cases, it was impossible to obtain a stable implantation. In two of these, a cemented implant was used. In the third patient, instability was not seen, leading to an 8 mm subsidence, along with thigh pain and distal hypertrophy of the femur. The 278 other patients had no intra-operative complications.

Late complications were:

1) 14 patients had a secondary subsidence of their device (1–4 mm), with a subsequent good stability and unaltered fixation to the skeletal tissue;

Introduction: Lateral meniscectomies lead to degenerative arthritis and therefore meniscus transplantation has been considered. In literature, this procedure appears to have good clinical results. The aim of this study was to evaluate our clinical results at mid-term follow-up and to correlate these results to the morphology and position of the transplanted meniscus.

Material and methods: Twenty-eight patients operated in 4 surgical centers, were retrospectively reviewed following lateral meniscal allograft transplantation. The mean age of the patients was 34 years (range, 18 to 50 years). Before surgery, all these patients suffered of permanent lateral femorotibial pain without radiological knee arthritis. The knees were all stable or stabilized, without axial malalignment of the lower limbs or corrected by a concomitant high tibial osteotomy. Arthroscopic procedure was performed for 9 patients and arthrotomy for 19 patients. Different techniques of fixation of the transplant were used, with or without bone plugs. The associated procedures were 2 ACL reconstruction, 3 high tibial varus osteotomies, and 1 mosaicplasty. The IKDC score were used for the analysis of the functional results. An arthroTDM or an arthro MRI was used to analyse the morphology and position of the transplanted meniscus.

Results: The mean follow-up was 35 months (range, 12 months to 6 years). The mean post-operative subjective IKDC score was 65.5 points (range, 19.5 to 89 points). There were 2 failures associated with a fast arthritic evolution and 2 functional bad results. The others 24 patients (85%) were satisfied or very satisfied, with a real improvement of the pain and the function. Seventeen patients (60%) have started again a sportive activity superior than the one pre-operating. At the last follow-up, all transplanted meniscus have healed, but the morphology and position of the transplanted meniscus was not always normal with absence of the middle segment in 3 cases; its extrusion in 9 cases, a posterior segment shortened or partially hurt in 5 cases and its absence in 3 cases. Better results were associated with good meniscus positioning and morphology.

Discussion: Our works confirm that lateral meniscal allograft is a therapeutic option with favourable results in terms of pain reduction and functional improvement in the medium term for symptomatic patients after lateral meniscectomy. Our results are comparable with those of the literature. The allograft is technically reliable, reproducible notably for the methods of fixation. A long term follow-up is necessary to evaluate the benefit of these grafts on the protection of the cartilage.

Acetabular components of total hip joint replacement (THJR) in previously irradiated pelvis show high rates of failure. We present a literature review and a retrospective series evaluating the survival of acetabular cages in this difficult situation. Our hypothesis was that cage reinforcement of the acetabulum after previous pelvic irradiation would lead to early failure.

A cohort of 11 patients (12 hips) was identified, who had undergone THJR utilising an acetabular cage, after previous pelvic irradiation for malignant tumours. All operations were performed by a single surgeon in Waikato over the period of 1997–2007. Six patients (six hips) died within one year of their operation, the further five patients (six hips) were analysed for survival and radiograpical loosening of the acetabular component. Complications attributed to previous irradiation are also reported.

There is a paucity of literature of THJR survivorship after pelvic irradiation. The first series from the 1970’s showed 50% acetabular loosening at 5 years in cemented cups. Two conflicting series are published with 44% vs. 0% failure of uncemented cups. Only one previous series (22 hips) reports the use of acetabular reinforcement rings, and showed a 20% loosening and 10% deep infection rate at 4 years. In our cohort of 12 hips in 11 patients, only five patients survived greater than one year after joint replacement. The average follow up of the remaining six hips is five years (two to ten years). Two out of six of the acetabular cages have catastrophically failed. Of the remaining four cages, one is probably, and three are possibly radiologically loose. Two out of six have raised concerns in regards to deep infection that were not proven microbiologically. Overall of the patients who survived greater than one year after their THJR for pelvic irradiation, only four out of six of the acetabular cages remained insitu, and all had concerns raised in regards to radiographical loosening.

We report a high rate of clinical and radiographic failure of cage reconstruction of the acetabulum after previous pelvic irradiation. A superior method of acetabular reconstruction in this difficult situation is yet to emerge. Alternative methods of reconstruction continue to develop, with trabecular metal options a possible consideration.

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.

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.

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.

Purpose of the study: Spontaneous repair of lost deep chondral tissue is minimal in the knee joint. A clinical trial of chondrocyte autografts as described by Brittberg and Peterson was undertaken by the Nantes University Hospital and the French Society of Arthroscopy in 1999.

Material and methods: Twenty-eight patients, mean age 28 years, underwent surgery in eight centers. Etiologies were: osteochondritis (n=14), isolated posttraumatic chondorpathy (n=7), chondropathy and full-thickness ACL tear (n=7). All lesions involved the condyles and were deep (ICRS grades 3 and 4). Mean surface area involved after debridement was 490 mm2 (range 150–1000 mm2). Patients were followed three years after the autologous grafting to assess functional outcome. An MRI was obtained at 2–3 years. Thirteen control arthroscopy procedures were performed including eight with biopsy specimens for histology and immunohisto-chemistry studies.

Results: Twenty-six patients were reviewed at more than two years. There were no general complications, three patients presented a partial avulsion of the graft treated by arthroscopy and one underwent arthrolysis at six months. Function improved in all patients except three and pain improved in all. The ICRS score improved from 43 points (range 19–70) to 77 points (range 39–84). Sixteen control MRIs were available and showed that the graft was hypertrophic in eleven cases, on level in four, and insufficient in one. Marginal integration was good in 11 cases and partial in five. Subchondral integration was complete in ten cases and mediocre in six. The arthroscopic score was nearly normal (score 8–11) in eight cases and abnormal in five (score 4–7). The histological class according to Knutsen (hyaline richness) was: one in group 1 (> 60%), three in group 2 (> 40%), four in group 3 (< 40%) and one in group 4 (bony or fibrous tissue). Function score (r=0.78 and MRI score (r=0.76) were correlated with arthroscopic sores. There was no correlation with the histological results.

Discussion: Clinical outcome was improved in more than 80% of cases, similar to results reported for histological series. The arthroscopic and histological results were equivalent to those reported by Knutsen but inferior to those reported by Bentley or Peterson.

Purpose of the study: The incidence and type of complications observed with arthroscopic procedures remains a timely subject, particularly as the use of new techniques becomes increasingly widespread.

Material and methods: In cooperation with the members of ISAKOS, The International Society of Arthroscopy, Knee surgery and Orthopaedic Surgery, we instituted two studies: a retrospective study of upper limb arthroscopy complications and a prospective incidence study during a 30-day inclusion period with patient review at one month and quality-of-life scoring.

Results: The retrospective study analyzed complications of 57,604 arthroscopic procedures of the upper limb performed by 99 surgeons from 38 countries. Neurological complications, though generally transient, were the most frequent and were related to traction, locoregional anesthesia or the operative technique. Four deaths were recorded, all anesthesia-related. The prospective study included 364 patients operated on by 50 surgeons. There were 16 initial complications (4.39%): material problem (n=12), three intraoperative bleeding (n=3), atelectasia (n=1). The rate of conversion was 2.47%. At one month, there were five complications reported in 133 patients (3.75%): anesthesia-related problem (n=1), bleeding (n=1), synovial fistula (n=1), reflex dystrophy (n=2). There were no infections and no neurological lesions. The one-month outcome was considered good or excellent by 98.5% of surgeons.

Discussion and conclusion: The results of these surveys are in agreement with data in the literature where the rate of complications is higher in prospective studies than in retrospective studies. The prospective study did not disclose any neurological complication while arthroscopy of the upper limb is generally considered to raise the risk of with this type of complication. This study recalls that although arthoscopy has enabled a decreased incidence in complications compared with open surgery, it is not a benign intervention and can produce complications.

Aim: The Low Contact Stress (LCS) Total Knee Replacements (TKR) is a well-established mobile bearing prosthesis with more than 25 year experience, while the Kinemax Plus is a well established fixed bearing prosthesis. We examined whether reproducing the joint line height to within 5 mm of the pre-operative joint line height had any impact on the clinical outcome in the two different types of Total Knee Replacements.

Method: 48 consecutive LCS knee replacements with a minimum of 2 years follow up had their pre and postoperative joint line (using Figgie’s method) and range of movement (ROM) measured. We used the Oxford Knee Score as a clinical outcome measurement tool.

A cohort group of 53 CR Kinemax plus TKR from the Bristol Knee group was matched for age and sex. They had the same parameters measured.

Results: Accurate joint line restoration was achieved significantly more frequently (P< 0.05) in the Kinemax group. Better post-operative ROM also occurred in the Kinemax group than the LCS, p = 0.03 and the former produced a bigger gain in ROM p < 0.01. However, no difference in the Oxford Knee Score existed between the two prostheses, p = 0.28.

Joint line: elevation K+ LCS

0–2 mm (16/48) = 33% (26/53) = 49% 2–5 mm (14/48) = 29% (14/53) = 26%> 5 mm (18/48) = 38% (12/53) = 25%

There was no significant difference in the ROM or Oxford Knee Score when the joint line was not elevated versus elevated for each prosthesis. However, there was suggestion that the ROM in LCS might be more sensitive to joint line changes, although this was not significant.

ROM

K+ LCS

Normal joint line 116° 105°

Elevated joint line 108° 101°

Conclusion: Accurate joint line restoration could not be shown to correlate with either improved ROM or Oxford knee score; probably because of the small mount of elevation encountered and the small study size. There was a significantly greater post-operative increase in ROM with the Kinemax Plus relative to the LCS, and a significantly closer restoration of the joint line with the Kinemax Plus, both with respect to the actual measurement and with respect to the proportion of cases in which the joint line was accurately reproduced. This is surprising since in most K+ cases additional distal femur had been resected to avoid a tight knee. While in the LCS group special efforts had been made to achieve accurate restoration of the joint level.

We reviewed the records of 107 consecutive patients who had undergone surgery for disruption of the knee extensor mechanism to test whether an association existed between rupture of the quadriceps tendon and the presence of a patellar spur. The available standard pre-operative lateral radiographs were examined to see if a patellar spur was an indicator for rupture of the quadriceps tendon in this group of patients. Of the 107 patients, 12 underwent repair of a ruptured patellar tendon, 59 had an open reduction and internal fixation of a patellar fracture and 36 repair of a ruptured quadriceps tendon. In the 88 available lateral radiographs, patellar spurs were present significantly more commonly (p < 0.0005) in patients operated on for rupture of the quadriceps tendon (79%) than in patients with rupture of the patellar tendon (27%) or fracture of the patella (15%). In patients presenting with failure of the extensor mechanism of the knee in the presence of a patellar spur, rupture of the quadriceps tendon should be considered as a possible diagnosis.

i. Purpose To determine whether operating in ultra-clean vertical laminar flow and personal isolation “space suits” reduces deep infection rates in total knee replacement compared to a conventional theatre and modern disposal gowns.

ii. Method An analysis of deep infection rates in 373 patients who underwent total knee arthroplasty performed in one operating theatre prior to and after a theatre and clothing upgrade.

Results The infection rate before the introduction of ultraclean air and space suits was 6/166 (3.6%). Afterwards the rate was 1/207 (0.5%). This shows a significant reduction (p< 0.05)

iii. Conclusion Compared to conventional theatres and clothing the use of ultraclean vertical laminar flow and spacesuits significantly reduces the risk of infection in total knee arthroplasty.

Purpose: We reviewed retrospectively 22 patients with recent and old fractures of the radial head treated with the GUEPAR radial head prosthesis which has a mobile metal cup derived from the GUEPAR gliding total elbow prosthesis.

Material and methods: Among the 22 patients, 13 underwent surgery in an emergency setting and four underwent a secondary procedure. Mean age was 41 years and follow-up was 18 months. The Mayo Clinic score was noted. Fractures were total or disengaged cervical fractures and in 72% of the elbows dislocation was associated. The coronoid process was fixed in one elbow, the olecranon in one and the medial ligaments were repaired in five. The status of the humeral condyle was examined in detail before insertion of the prosthesis. We also were particularly attentive concerning the height position of the prosthesis.

Results: There were no complications. Outcome was good among the patients undergoing an emergency procedure with a mean Mayo Clinic score of 83/100, mean force 75%, good motion, particularly 77° pronation, and 79° supination, with good stability and absence of wrist problems. The patients who underwent a secondary procedure had less satisfactory results, particularly for motion (44° pronation and 54° supination). The distal radioulnar index was not perfectly restored. Finally four patients had arthrolysis for limited flexion/extension, three of them in the secondary group.

Discussion: Resection of the radial head is an alternative for complex fractures that has its inconveniences. The first is that it destabilises the elbow in valgus position in the event of injury to the medial ligaments and the second is the ascension of the radius in the event of injury to the interosseous membrane. Fixation is another alternative, but it is difficult and has not provided good results in our hands or in the literature (we have compared this series with a series of 20 fixations for equivalent fractures). The prosthesis appears to be a good solution: it stabilises the elbow, prevents ascension of the radius, allows early rehabilitation, and provides good subjective outcome, particularly in emergency cases.

Purpose: A prospective multicentric study was conducted in a concentric and consecutive series of 204 patients operated on between Mai 1999 and August 2001 for fracture of the proximal femur. The purpose of this study was to assess quality of life after surgery in patients undergoing implantation of the Intermedia® prosthesis.

Material and methods: Mean patient age was 79.6± 8.6 years), 18.8% men. Most of the fractures were Garden III and IV fractures (87.4%) and 90.9% were recent (< 21 d). The intermediary Intermedia® prosthesis was implanted via the posterolateral approach in 73.9% of the patients with acetabular preparation in 13.7%; a head with a restraining skirt was used in 20.8%. The Robinson score for motion, lifestyle, degree of osteoporosis (Singh score), history (ASA), psychomotor index (Hodkinson score) were determined preoperatively (19/26 (±6.89). The Merle d’Aubigné score was calculated at one year. Adaptation of the femoal stem (3 sizes) to the shaft was assessed on standard x-rays. The Kobayashi method was used to study stem to shaft fit; this score gives a rate of shaft filling used to determine whether the self-blocking contact was well achieved with the three stem sizes available.

Results: There were eleven (5.4%) posterior dislocations including four which were reduced orthopaedically. Among the 203 patients, 40 (19.7%) were lost to follow-up and 34 died. The Merle d’Aubigné score at one year showed 84.7% satisfactory results (excellent, very good, good). Preoperatively 59% of the patients were independent and 7% resided in nursing homes, these figures at one year were 55.5% and 5% respectively. Radiologically, the rate of migration (impaction) was 3.9% at one year. Stem-to-shaft fit was, according to Kobayashi for the proximal, middle, and distal portions 73%, 75% and 75% respectively.

Discussion: Mortality due to fracture of the proximal femur is high (16.7% at one year). Morbidity was due to infection (1%) and eleven displacements (5.4%). The difference in motion and lifestyle between the pre- and postoperative period was not significant. Simplification of the implantation procedure by using three stem sizes did not produce any radiological differences at one year.

Purpose: This study was conducted to analyse the importance of the Malgaigne notch and its position on standard x-rays taken in internal rotation or on arthroscan in patients treated for anterior instability of the shoulder. Our purpose was to search for criteria perdictive of outcome of arthroscopic stabilisation of the shoulder joint using the Bankart method.

Material and methods: Fifty-four patients were reviewed to determine the postoperative Duplay score. Mean follow-up was 68 months (32–100). Mean age at surgery was 29 years. We divided the patients into three populations as a function of preoperative symptoms: population A two dislocations or more, population B one dislocation then episodes of subluxation, population C no dislocation but pain. We divided this population according to the Duplay score. Group 1 patients had a fair or poor outcome, Group 2 patients had a good or excellent outcome. We reviewed 54 radiograms using patterns of increasing size (mm by mm) to assess the radius of the humeral head and the depth of the notch. We evaluate the reproducibility of this method by comparing the readings of ten senior orthopaedic surgeons. There were no false positives or false negatives. Variance of the measures taken by the ten surgeons was 0.67 at 1.31 mm, a small variance. We compared the ratio between the radius of the humeral head and the depth of the notch in the different groups.

Results: The Malgaigne notch was significantly deeper in population A (19%) than in population B (14%) or population C (14.3%). This suggests that the size of the notch has an effect on symptomatology of shoulder instability. The notch was also significantly deeper in group 1 patients (fair or poor outcome) (21%) than in group 2 (good or excellent outcome) (16%) (p=0.05).

Discussion: Beyond a threshold set at 15%, there were 54% fair or poor results. The position of the notch in height was significantly different in population A compared with populations B and C (p=0.01). It appears to be higher in case of true recurrent dislocation. We did not demonstrate any statistical link between the position of the notch on the CT scan and surgical outcome. This study demonstrates the importance of information on the internal rotation images in choosing the proper type of surgery for shoulder instability.

Purpose: It is known that severe distention of the inferior glenohumeral ligament (IGHL) during anteror-inferior shoulder instability is an important factor of poor functional prognosis after arthroscopic stabilisation. O. Gagey proposed a clinical test to assess laxity of the IGHL. The purpose of this study was to assess the laxity of the IGHL using a dynamic radiological test (AP view in passive abduction of the glenohu-meral joint) and to correlate findings with arthroscopic observations..

Material and methods: We performed a prospective study in 21 patients scheduled for arthroscopic stabilisation for anteroinferior shoulder instability. Mean age was 24.6 years, 17 men and 4 women. The test was performed in the supine position with a strictly AP view of the shoulder. Bilateral comparative images were obtained. The shoulder was brought to forced passive abduction in neutral rotation without general anaesthesia or locoregional anaesthesia. The angle between the axis of the humeral diaphysis and the line passing through the inferior border of the glenoid cavity and the lateral border of the scapular tubercle was measured. Vuillemin has demonstrated that this test is reliable and reproducible. During arthroscopy performed for diagnostic and therapeutic purposes, the degree of distension was quantified using the Detrisac classification of four stages. We considered that stages 3 and 4 were frank pathological distension. We used the threshold of 15° for the difference between the healthy and pathological side for the radiological test. We assessed the ability to demonstrate severe laxity of the IGHL.

Results: For differences in abduction less than 15°, the test sensitivity was 77%, specificity 91%, positive predictive value 87% and negative predictive value 84%.

Discussion: A careful physical examination and appropriate complementary tests are essential for the evaluation of anteroinferior instability of the shoulder joint in order to obtain a precise diagnosis and search for contraindications for arthroscopic cure. The rate of recurrence after arthroscopic stabilisation remains above that obtained with open techniques. It has been demonstrated that major laxity of the IGHL constitutes a relative contraindication for arthroscopic stabilisation. Radiographic measurements provide precise information for evaluating the laxity of the IGHL. Taking a positive threshold of 15° difference identifies 87% of the cases of Detrisac stage 3 or 4 ligament distension.

Conclusion: We propose a preoperative complementary test using standard x-rays together with our dynamic radiological test of passive shoulder abduction. If the difference between the healthy and pathological side is greater or equal to 15°, the therapeutic strategy should include not only reinsertion of the rim but also retight-ening the ligament complex, or open stabilisation.

The purpose of this study was to determine whether a laminar flow operating system reduces deep infection rates in Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA) and to examine the costs involved in implementing laminar flow technology. A retrospective analysis of deep infection rates in 759 patients who underwent THA and TKA was performed in one hospital prior to and after the introduction of a vertical laminar flow operating system together with the use of isolation body exhaust suits. A cost analysis was also performed on the cost of implementing laminar flow technology and the average inpatient hospital cost of managing a deep infection. A control group consisted of 387 THA and TKA performed in 2 years in a conventional operating theatre and follow up carried out to a mean of 29 months. There were 12 recorded deep infections, 3.1%. Case group consisted of 372 THA and TKA performed in 2 years after the introduction of a vertical laminar flow operating theatre together with the use of isolation body exhaust suits, with a mean follow up to 22 months. There were 4 recorded deep infections, 1.1%.

A comparison of deep infection rates yielded p value 0.06. There was a strong trend toward a reduction in deep infection rate in THA and TKA performed in the laminar flow theatre with the use of isolation body exhaust suits. The economic impact of deep infection in THA and TKA is vast and the cost of implementing laminar flow technology must be weighed against the deep infection rate as well as the number of operations performed at an institution.

The passage of bacteria through surgical drapes is a potential cause of wound infection. Previous studies have shown that liquids and human albumin penetrate certain types of drapes¹². We studied the passage of bacteria through seven different types of surgical drape and an operating tray. We also studied the effect of different wetting agents on the passage of bacteria through wet reusable woven drapes. Bacteria were grown on an overfilled whole horse blood agar plate. The plate was covered with the drape to be tested and a second agar plate was inverted and placed on the drape. After 30 minutes the second agar plate was removed, incubated and inspected for bacterial growth. The experiment was repeated removing the second plate at 60 minutes and then again at 90 minutes. The entire experiment was repeated for each drape and then for each wetting agent.

Bacteria easily penetrated all the woven reusable fabrics within 30 minutes. The disposable non-woven drapes proved to be impermeable up to 90 minutes, as did the operating tray.

Chlorhexidine and Povidone-Iodine were demonstrated to slow, but not stop the passage of bacteria through reusable woven drapes. Normal saline and human blood accelerated the passage of bacteria through reusable woven drapes. We recommend the use of non-woven disposable drapes or woven drapes with an impermeable operating tray, in all surgical cases.

Tibial fractures represent a heterogeneous group of fractures that are difficult to treat and vary widely in their time to union. Judging when it is safe to remove an external fixator or plaster cast requires clinical and radiological assessments both of which are subjective. Any errors in determining when a fracture has healed can lead to a prolonged treatment time or to refracture. Many methods have been employed to attempt to define clinical union in an objective manner including ultrasound, DEXA scanning, vibration analysis, and fracture stiffness measurements. Stiffness measurements are however time consuming to perform, of debatable clinical significance, and applicable only to fractures treated with external fixators. It has been previously observed^1,2 that weight bearing increases with time post-fracture. It has also been suggested³ that the ability of a patient to weight bear on the fractured limb is controlled by a biofeedback mechanism of biological self-control of fracture site strain that will be related to the stiffness of the fracture. We hypothesised that weight-bearing will be closely related to fracture healing and could be used as an alternative measure of healing where other objective measures of healing are not available or are impracticable.

A group of ten patients with tibial fractures treated by external fixation were studied. Using a Kistler force plate set into the floor, ground reaction forces for both lower limbs (fractured and non-fractured) were measured during normal walking at three weekly intervals. Concurrent fracture stiffness measurements were made using the Orthofix Orthometer.

In 8 patients who made good recoveries, the fixator was removed between 15–20 weeks post injury when the fracture stiffness had reached a minimum of 15 Nm/deg. Weight-bearing through the injured leg was seen to approach 90% of that through the uninjured leg in the 3 weeks prior to fixator removal. Two patients with delayed union achieved weight bearing of less than 40% of normal between 15–20 weeks. They also demonstrated low values of fracture stiffness (< 5 Nm/deg.) and subsequently required operative intervention to achieve union.

In this small study of 10 patients, weight bearing appears to correlate well with clinical union. It is quicker and easier to assess than stiffness and potentially has relevance to other fixation methods. We are continuing these measurements on conservatively treated, intra-medullary nailed, and externally fixed tibial fractures.

Aim: To study the complications of an extended lateral femoral osteotomy (after Paprosky) of the femur utilised for exposure in revision total hip replacement.

Method: A retrospective audit was performed of the senior author’s revision hip patients who had, at the time of surgery, an extended lateral femoral osteotomy for both deformity correction and to facilitate cement removal. No attempt was made to correlate the use of an osteotomy and operating time or overall results as no unbiased control group was available. The time to radiological union and complications of the procedure was reviewed to assess the safety of an osteotomy in one surgeon’s practice.

Results: Thirty patients with 31 osteotomies were reviewed, all with long-stem fully porous coated femoral stems. It was the senior author’s anecdotal opinion that osteotomy facilitated cement removal without canal perforation and was necessary for varus deformity correction in many patients. All osteotomies united without further procedures after an average of 22 weeks (range: 12 to 38 weeks). There was one fatigue fracture of the osteotomised fragment, one non-union of the greater trochanter and two cable failures; all without significant sequelae. There was one fracture of the medial proximal femur that required a period of four weeks of bed-rest; otherwise all patients were mobilised full weight bearing as tolerated. One patient had deep infection and a loose femoral component. Two patients had instability of the hip in the post-operative period.

Conclusion: We have shown that the osteotomy reliably united and was safe even with early full weight bearing, with few complications. Extended femoral osteotomy for deformity correction and cement removal in revision hip replacement is a safe and easy technique that reliably facilitates revision.

Purpose: The risk of recurrence would be greater after arthroscopic treatment of shoulder instability compared with open repair. We wanted to find what effect bone lesions and more particularly posterosuperior notch in the humerus have on outcome after arthroscopic management of shoulder instability.

Material and methods: We made a retrospective analysis of 60 patients who underwent an arthroscopic procedure between February 1993 and December 1998. Mean age was 28 years three months. All patients in this series had a bony notch measured on the preoperative scan. Six measurements were made to determine the volume of the notch approximated to the half volume of a revolution ellipse. The ratio of this volume to total volume of the humeral head (approximated as a sphere) was also calculated. The glenoid cavities were classed in four groups: normal, abrasion, fracture, amputation. Operative result was assessed with the Duplay score at a mean follow-up of 42.7 months.

Results: Outcome was excellent in 24 patients, good in 14, fair in seven, poor in five including four related to recurrent instability, and a failure in ten requiring reoperation. The rate of recurrence with reoperation was 16.6%. Notch volumes varied from 0 to 4792 mm³ (mean 1019±1253). The notch/ head ratio ranged from 0 to 10.5% (mean = 2.28±2.63). Only 12 patients (20%) did not have a bony notch; 11 of them had an excellent or good result. Mean volume of the notch in patients with excellent, good, or fair outcome (group A) was 639.72 mm³. Mean volume of the notch in the failure cases (group B) was 2158.11 mm³. Glenoid cavity classes in group A were 17 normal, 20 abrasion, 8 fracture, 0 amputation. In group B the classes were 2 normal, 9 abrasion, 2 fracture, 2 amputation. The volume of the notch was significantly correlated with outcome (Spierman test). There was no significant correlation for the glenoid cavity.

Discussion: Despite the absence of a significant correlation with the glenoid cavity classes, the presence of a glenoid lesions in cases with a bony notch smaller than 500 mm³ had an important impact in three out of the four failures (two amputations and one fracture). Considering a threshold value of 1000 mm³, the rate of failure was 7.7% irrespective of the glenoid lesions and 52.5% if glenoid amputations and fractures were excluded.

Conclusion: It would appear that arthroscopic treatment should be reserved for patients with a small humeral notch (< 1000 mm³). Glenoid lesions should also be quantified in patients with small notches.

Purpose of the study: We compared in vitro the efficacy of screw-plate fixation versus double screw fixation on a model of type 2 Schatzker fracture of the lateral tibial plateau.

Materials and methods: Ten screw-plate fixations using a lateral prebent plate and 10 double-screw fixations (6.5 mm screws) were made on 10 pairs of non-embalmed cadaver knees after simulation of type 2 Schatzker fractures. The strength of each fixation was tested with a compression device. Criteria indicating failure were displacements greater than 2 mm of one or more fracture lines. The force applied at rupture and the stiffness of each type of fixation were compared. Wilcoxon’s test was used for statistical analysis.

Results: Force at rupture and stiffness of the fixation were similar for the two types of fixation. There was no statistical difference (p > 0.05) between the screw-plate and the double-screw fixations.

Discussion: Our findings on a model of type 2 Schatzker fractures are in agreement with previous data obtained by other authors working on models of type 1 Schatsker fractures. The biomechanical stability of the double-screw fixation is as good as that obtained with screw-plate fixation for the treatment of fractures of the lateral tibial plateau.

We performed a randomised, prospective trial to evaluate the use of unreamed titanium nails for femoral fractures. Of 48 patients with 50 femoral fractures 45 were followed to union; 23 with an unreamed and 22 with a reamed nail. The study was stopped early because of a high rate of implant failure.

The fractures in the unreamed group were slower to unite (39.4 weeks) than those in the reamed group (28.5 weeks; p = 0.007). The time to union was over nine months in 57% of the unreamed group and in 18% of the reamed group.

In the unreamed group 14 secondary procedures were required in ten patients to enhance healing compared with three in three patients in the reamed group. Six implants (13%) failed, three in each group. Four of these six fractures showed evidence of delayed union.

To achieve quicker union and fewer implant failures we recommend the use of reamed nails of at least 12 mm in diameter for female patients and 13 mm in males.

We studied the effect of 'dynamisation' on tibial fractures in six patients treated by the Dynamic Axial Fixator. In the early stages, peak cyclic movement at two to four weeks averaged 0.75 mm (0.19 to 1.02) on the medial side of the bone and 0.86 mm (0.21 to 1.25) on the lateral side. The amount of movement correlated with the applied load and the fracture stiffness. After unlocking the fixator column at six weeks, progressive closure of the gap averaged 1.3 mm (0.1 to 3.5). Cyclic movement is produced by early weight-bearing with the fixator column locked. Progressive closure occurs after unlocking the column, and is often associated with a reduction in cyclic movements. The effects of dynamisation on movement at the fracture site should be defined separately, in terms of cyclic movement and of progressive closure.

The changes in serum adjusted ionised calcium and parathyroid hormone (PTH) were prospectively studied in 32 patients with isolated tibial fractures, treated conservatively. We measured serum albumin, adjusted total calcium, phosphate, pH, adjusted ionised calcium and PTH at intervals until the fractures had healed. The mean ionised calcium adjusted for pH fell within 24 hours of injury, and then rose to a peak at between four and six weeks. These changes cannot be explained by changes in serum pH or PTH. The restoration of normal ionised calcium levels after fracture coincided with the period when the callus was being calcified. Analysis of the changes in ionised calcium, phosphate and PTH suggests that PTH levels alter in response to changes in ionised calcium levels. PTH is highest immediately after fracture and lowest, often not recordable, at six weeks. The cause of the changes in the ionised calcium level has yet to be elucidated.

We examined specimens of hydroxyapatite-coated femoral prostheses from four patients who had died within nine months of implantation for fractured neck of femur. Histology showed newly formed immature bone overlying the hydroxyapatite coating with new trabeculae bridging to the endosteal bone layer. In the diaphysis, where there had been contact between the hydroxyapatite and the cortex, there was dense, firmly anchored bone with an haversian architecture. In other places the newly formed bone had a trabecular structure, containing bone marrow tissue with normal cellularity. It appeared that biological osseointegration had taken place.

A method of assessing foot movement suitable for use in clinical practice is presented. The method assesses the component of movement in the horizontal plane which is produced by rotating the calcaneum about the axis of the subtalar joint.

Radiopharmaceuticals have been successfully used to detect occult neoplasms and infective lesions. Bone scans using 99mTc-labelled methylene diphosphonate located osteoid osteomas accurately in a series of 30 symptomatic patients. A portable radiation detector system has been designed to help intra-operative localisation and facilitate complete excision of the lesions with minimal damage to normal tissue. A sodium iodide detector with a fibre-optic link was used at first, but a cadmium telluride system has provided a more durable, reliable and sensitive sterilisable probe.

Thirteen patients with ruptures of the calcaneal tendon diagnosed more than four weeks after injury were reviewed. Eleven patients had operative reconstruction with tendon shortening and the postoperative follow-up ranged from one to seven years. Isometric and isokinetic measurements, as well as the strength of the triceps surae, all compared favourably with the normal contralateral leg. Only one tendon re-ruptured. Eight of the eleven patients were satisfied with the results and the two patients who had refused reconstruction had worse functional results. Late reconstruction of a ruptured calcaneal tendon is thus a worthwhile procedure.

A 13-year-old girl presented with a two-year history of pain in the right thigh and right forearm. Engelmann's disease was diagnosed on the basis of radiological appearances and histological examination of the bone. Her symptoms subsided after biopsy of the bone, but two weeks later she developed severe pain in the left tibia and was unable to walk. Radiological features of Engelmann's disease were found in the left tibia and other long bones although these bones had been radiologically normal one month previously. Treatment with prednisolone gave rapid relief of pain and allowed the patient to become mobile again. Four months later the radiological appearances showed significant improvement. The use of corticosteroids in this disorder is discussed.

Between March 1969 and May 1978, 36 babies sustained birth injuries of the brachial plexus at the National Women's Hospital, Auckland, New Zealand. This gives an incidence of 0.87 per 1000 live births. Nearly 80 per cent of these children had made a complete recovery by the age of 13 months, while none of those with significant residual defects has severe sensory or motor deficit of the hand.

Seventy-nine cases of fracture of the femoral shaft treated by cast-brace and early walking have been reviewed. Discrepancy in femoral length was assessed by scanogram. The cases were analysed to relate the incidence of shortening greater than 2 centimetres to the type and site of the fracture, and the time which elapsed from injury until the cast-brace was applied. Such shortening was encountered most frequently when the cast-brace was applied within the first two weeks from injury or after six weeks and in those patients with comminuted fractures of the middle third of the femoral shaft.

1. Ectopic ossification is commonest in, but not confined to, traumatic paraplegia. It occurs also in many other neurological disorders which have in common a gross disturbance of spinal cord reflex activity. It is a true ossification and must be distinguished from calcification.

2. The neurological lesion may lie anywhere from the cerebral cortex to the mixed peripheral nerve. It may involve motor tracts, sensory tracts or a mixture of both.

3. The ossification is localised and self-limiting. It occurs mainly in the lower limbs and is restricted to certain muscles or muscle groups, the nerve supply of which is always below the level of the central neurological lesion.

4. The blood chemistry is usually normal.

5. A true arthropathy is rare except as part of a secondary suppurative arthritis.

6. The resemblance to myositis ossificans progressiva or to ossifying haematoma is only superficial, although the pathological process at cellular level may be the same.

7. The period of onset after paraplegia is variable. The earliest recorded example is in one of our own cases in which ossification occurred nineteen days after injury. Other patients have developed ossification after several years.

8. The condition is commonest in acquired nervous disease rather than in congenital disorders, and so far as we know it has not been described in the myopathies. The presence of muscular spasticity or flaccidity is relevant only in that it indicates a disturbance of reflex activity.

9. Soft-tissue ulceration appears to be frequently associated with ectopic ossification. The type of new bone formation associated with large chronic ulcers is not to be compared with the new bone formation in the muscles of a paraplegic patient in otherwise good general condition.

10. The occurrence of urinary tract infections with calculi and generalised sepsis is not specifically related to the onset of new bone formation.

11. Localised soft-tissue oedema often precedes the formation of new bone. Its appearance is undoubtedly important, but the mechanism of its origin is obscure.

12. It is not yet known what initiates ectopic ossification, what limits its spread and what finally causes it to stop.

13. We have described 100 examples of ectopic ossification in 603 paraplegic patients.

14. Surgery has been required in only eight patients. The only indication for surgery is bony ankylosis of the hip in an unacceptable position.

1. Paraplegia from fracture-dislocation at the thoraco-lumbar junction is a mixed cord and root injury. The root damage can be distinguished from cord damage by neurological examination and by comparison of the neurological level with the fracture level.

2. Even though the cord injury is complete, as it usually is, the roots often escape or recover.

3. Fracture-dislocations can be divided into stable and unstable types. Because of the possibility of root recovery care must be taken to prevent further damage to the roots by manipulation of the spine or during treatment. For this reason unstable fracture-dislocations are fixed internally by plates.

4. Internal fixation also assists in the nursing of the patient. The nursing technique and the care of the bladder are described.

A survey of this type cannot be used to point to any definite factor or factors predisposing to the development of hallux valgus. Nevertheless, a comparison of measurements in the morbid and control groups shows several outstanding differences:

1) There was a high degree of correlation between valgus and intermetatarsal angle in the two groups combined (coefficient, 0·7) but the correlation was higher in those cases with a degree of valgus greater than 25 degrees than in the remainder (coefficients, 0·36 and 0·53).

2) In the control group the first metatarsal was longer than tile second by a mean measure of 2 millimetres; in the morbid group by a mean measure of 4 millimetres. For a high degree of valgus and a low intermetatarsal angle the first metatarsal tends to be longer than the second by a significantly greater amount than when the high valgus is associated with iligh intermetatarsal angle.

3) In 90 per cent of the control cases there was a lateral displacement of the medial sesamoid of the first metatarsal of 3 degrees or less, whereas 88 per cent of the morbid group showed a displacement of 4 degrees or more. There was very little overlap in the distributions of this observation in the two groups. There was a high correlation between the degree of this displacement and the severity of hallux valgus.

4) Rotation of the hallux was not observed among the controls; in the morbid group those cases showing rotation had an average degree of valgus of 36 degrees while the rest had an average of 19 degrees. The mean degree of valgus in the morbid group was 32·0 degrees and that of the controls 15·5 degrees. The mean angle between the axes of the first and second metatarsals was 13·0 degrees in the morbid group and 8·5 degrees in the controls.

Since tile morbid group consisted largely of women (98 per cent) it is important to know that in the control group the only measure showing a statistically significant sex difference is that of intermetatarsal angle, but that, even so, the mean difference is only 1·3 degrees. Thus tile sex difference between the two groups is probably only of minor importance. The role of age in influencing the observations cannot be clearly elucidated from the data at present available. It can only be stated that there is no positive indication that age is a controlling factor in the departure observed in the morbid group from the control observations.