Limb length disparity is a frequent complication after hip surgery inducing many surgeon-patients conflicts. To date no study has been able to precisely quantify such limb length disparity. EOS® system, currently validated to measure lower limb parameters, allows from two bi-dimensional numerical orthogonal radiographies in standing position to obtain a tri-dimensional reconstruction of lower limbs. A computerized system achieves the parameters calculation.

The aim of this study is to precisely measure the limb length disparities and the other hip parameters following total hip arthroplasty surgical procedure, by using a standard X-rays and using EOS® three-dimensional reconstructions.

Twenty-eight patients programmed for total hip arthroplasty have been included (i.e. thirty lower limbs). Two independent performers have carried out twice the measures either on standard X-rays and using three-dimensional reconstructions of the lower limb disparities prior and after the surgical procedure.

The inter and intra-observer reproducibility for the measure of the lower limb disparities have been of the EOS® measures have been respectively of 0.854 and 0.865 and for the standard X-rays of 0.717 and 0.726.

Mean length disparity observed was before Total Hip Arthroplasty of −0.328 cm (0.705; −1.266/0.530) and was of 0.088 mm (1.326; −1.635/0.632) after. We are able to decrease the lower limbs disparity in 69.1% and for the average of 0,416cm.

Using EOS® system has allowed assessing with greater precision the possibility to restore equal lower limb length.

This assessment has permitted introducing a new planning procedure including EOS® imaging associated to the fusion of the prosthetic tri-dimensional image in order to achieve adequate lower limb length.

Hard-on-hard bearing surface have been accepted as a valuable alternative for young and active patients needing a hip replacement because these combinations are resistant to wear. Initial development of alumina-on-alumina bearings faced complications such as fractures, and socket loosening. But, with the increasing number of prostheses implanted, noise occurrence appeared as a new complication. The primary aim of the present survey was to quantify the prevalence of having noise in a population receiving alumina-on-alumina hip arthroplasty.

Two hundred and eighty-four ceramic-on-ceramic hips were performed in 238 patients (126 males and 112 females) from January 2003 to December 2004. The average age at the index operation was 52.4 ± 13.4 years (range, 13 to 74 years). We used the same type of prosthesis for all patients manufactured in all cases by Ceraver-Osteal^®. Clearance between femoral and insert was between 20 and 50 microns in order to achieve minimal wear. The survey was conducted by an independent surgeon who did not participated in patients care during the last 6 months of 2007. He interviewed the patients by phone with a standardized questionnaire (appendix) that aimed to assess if noise was present and the characteristics of this noise if present. No suggestion was done on how they could describe the noise and they felt free to use the word that they considered to be the most adapted. Satisfaction was evaluated asking if the patient was very satisfied, satisfied or dissatisfied with its prosthesis.

When the noise was present, the X-ray was independently evaluated to assess if sign of component fracture was present.

Four patients (six hips) died of unrelated cause during the follow-up. Three patients (three hips) lived outside France and could not be followed (1.3%). Nine patients (ten hips) could not be traced and are considered lost to follow-up (3.8%). Two hundred and twenty-two patients with 265 hips were therefore surveyed. Among these 265 hips, 28 experienced noise generation (10.6%). It was defined as a snap for 6 patients, as a cracking sound by 6, as rustling by 6 patients, as a squeaking by 7 patients (2.6%), a tinkling by 2 patients, one patient was unable to define the sound she felt. No factor related to the patient influenced the occurrence of noise. Twelve patients were dissatisfied with the result of the hip prosthesis, 5 of them experienced noise (41.7%); 210 were satisfied or very satisfied 23 of them experienced noise (11%); this difference was significant (p=0.002). No patients required revision for noise.

The origins of noise occurrence are unknown but several hypotheses can be suggested.

Squeaking may be due to absence of sufficient lubrication. Other types of noise can be due to microseparation, occult dislocation, impingement between the femoral neck and the acetabular rim but demonstration remain an issue.

Introduction: While an increasing number of authors have reported on the long-term results of primary alumina total hip arthroplasty (THA) [1], strategies for revising a ceramic-on-ceramic THA are debated in the literature. According to some authors [2], the reimplantation of a ceramic head on a well-fixed femoral stem is inadvisable, as it may lead to a fracture of the newly implanted head. The aim of the present study was to evaluate the incidence of this specific issue, and to report on the clinical and radiological results of the revised hips.

Methods: Between January 1977 and December 2005, 138 consecutive alumina-alumina revision hip arthroplasties were performed in 127 patients. There were 79 women (62.2%) and 48 men (37.8%), with an average age of 67 years (range, 32–91 years). Among these, an isolated acetabular revision was performed in 108 cases. The reason for revision was aseptic loosening of the acetabular component in 98 hips, pain in 7, fracture of an alumina liner in 2, and recurrent dislocation in 1. The revised socket was a cemented alumina in 56 hips, a threaded screw-in titanium with an alumina core in 34, a pressfit titanium with an alumina core in 11, and bulk alumina in 7. Acetabular bone stock losses were classified according to the AAOS system. Most of the hips had a contained type II defect (86%). In all cases, the femoral stem was left in place and the acetabular component alone was revised. At the time of revision surgery, an aluminaalumina combination was implanted in 27 hips, an aluminapolyethylene combination in 56, a metal-poly-ethylene combination in 15, and a zirconia-polyethylene in 10. Overall, a ceramic head was reimplanted on a used femoral taper in 59 cases. Acetabular reconstruction with allografts supported with the Kerboull acetabular reinforcement device was performed in 31% of the hips.

Results: The mean follow-up period was 78 ± 37 months. Thirteen patients (15 hips) died a mean 37 months after surgery. Sixteen patients were lost to follow-up. Postoperatively, five hips had a recurrent dislocation, 2 a deep infection, 9 a trochanteric nonunion (21,3%), 6 a transient nerve palsy. 18 hips required a re-revision surgery, 12 of which for aseptic loosening of the acetabular component. Among the 59 ceramic heads implanted on a well-fixed stem, no fracture of the head occurred at a mean 81 months follow-up. Of the original 108 hips, 77 were available for clinical evaluation and 75 for radiological evaluation at least 2 years after surgery. The mean Merle d’Aubigné score increased from 10.1 ± 2.1 to 16.7 ± 1.1 at the latest follow-up (p< 0.001). Forty-five hips were graded excellent or very good (60%), 26 good (34,6%), 3 fair (4%), and 1 poor (1.3%). When revision for aseptic loosening was considered as a failure, the overall survival rate at 8 years was 96.3 ± 1.8%.

Discussion & Conclusions: In the present study, aseptic loosening of the acetabular component was the main reason for revision surgery. Osteolysis around ceramic implants was moderate and was related to the migration of the socket. Among the ceramic heads implanted on a used titanium trunnion, no fracture was observed. This approach is possible, in so far as careful inspection does not show any major imperfection of the morse taper [3]. As for other bearing surfaces, the management of aseptic loosening of al-al prostheses is based on the amount of osteolysis around the loosened socket.

Purpose of the study: TKA on genu valgum raises serious problems for the ligament balance. Excessive release of the lateral retracted ligaments exposes the knee to potential instability in the frontal plane. To resolve this problem and avoid implantation of a constrained TKA, we opted for osteotomy of the lateral condyle removing the insertion of the lateral collateral ligament and the popliteal muscle after release of the fascia lata. The purpose of our study was to evaluate the functional and radiographic outcomes of these patients.

Material and methods: This was a retrospective study from 2002 to 2006. All patients with degenerative joint disease of the knee with severe and/or fixed genu valgum were included. These patients were implanted with a navigated posterostabilised Wallaby TKA (Navitrack) associated with osteotomy of the lateral condyle fixed with screws after acquisition of the ligament balance. The diagnosis and surgical history were noted. The preoperative alignement was determined on the full limb x-ray and from navigation data. The following variables were reviewed: polyethylene height, lowering of the lateral condyle, blood loss, operative time. The postoperative alignment was established at least one year after surgery. Intraoperative, postoperative and late complications were noted. The Knee Society function scores were used.

Results: Fifteen patients, mean age 70 years were reviewed at mean 35 months. The mean duration of the operative time was 136 min with mean blood loss of 620 ml. The mean PE height was 13 mm. All operated knees were corrected with mean alignment improving from 17.71 to 1.5 valgus postoperatively. The function score improved from 35 preoperatively to 79 at last follow-up. There were no cases of patellar instability or secondary laxity. Two patients developed late reflex dystrophy. The only case of revision concerned one non-union of the lateral condyle (screw removed at four months) but had a function score of 85 at last follow-up.

Discussion: Performing an osteotomy of the lateral condyle in complement with the navigated posterostabilised TKA for fixed genu valgum enabled good relaxation and satisfactory functional results so that totally constrained implants can be avoided.

Purpose of the study: Leg length discrepancy after THA is a common complication and source of recurrent complaints from patients. To date, no reliable and reproducible technique has come forward to enable accurate quantification of all radiological parameters of the lower limb. Nevertheless, preoperative planning for hip arthroplasty requires knowledge of many limb parameters, in particularly leg length discrepancy, femoral offset, or the head-neck angle. The most widely used method is to use the 2D radiographs. The EOS system uses two digitalised 2D images taken orthogonally in a weight-bearing position to enable 3D reconstruction of the lower limb. The inter- and intraoperator reproducibility has been studied and validated. The purpose of our study was to compare the inter- and intra-operator reproducibilities of the measures taken on the standard full-length x-ray and those determined on the 3D EOS reconstructions.

Material and method: Twenty-five patients scheduled for THA were included in this study (50 lower limbs). Two independent operators determine the measures on the AP EOS view and on the 3D reconstructions obtained from two orthogonal EOS images. The following parameters were measured: femur length, tibia length, limb length, HKA, HKS, femoral offset, neck-shaft angle, head diameter, and length of the femoral neck. Each observer performed two series of measurements. Interobserver reproducibility was assessed with the intraclass correlation coefficient (CI: 95%). Student’s t test was used to compare the clinical parameters measured on the 2D and 3D images.

Results: Inter- and intraobserver reproducibility were 0.867 and 0.903 on the 2D x-rays and 0.911 and 0.940 on the 3D reconstructions. The better reproducibility of the EOS reconstruction was confirmed for all parameters tested in this study. Comparison of the 3D and 2D measurements revealed significant differences.

Discussion: Our study demonstrated that measurements made on EOS 3D reconstructions offer better inter- and intraobserver reproducibility than those made on the standard AP view. In addition, the 3D reconstruction takes into consideration of the projection of the anatomic structures in the plane of the AP radiograph. The EOS appears to be a pertinent tool giving reliable results for the pre- and postoperative work-up for arthroplasty of the lower limb.

To date, no technique has proved to be reliable and reproducible in order to precisely calculate radiological lower limb parameters.

EOS^® system allows from two bi-dimensional orthogonal radiographies in standing position to obtain a tridimensional reconstruction. A computerized system achieves the parameters calculation.

The aim of the study was first to evaluate the inter and intraobserver reproducibility of the EOS^® system, secondly to compare EOS^® measures with X-ray orthoroentgenograms.

Twenty-five patients about to receive total hip arthroplasty were included (fifty lower limbs). Two independent performers have carried out twice the measures either on standard X-rays and using three-dimensional reconstructions (femoral parameters (length, offset, collo-diaphy-seal angle, neck length, and head diameter), tibiae length, limb length, HKA, HKS). The reproducibility was estimated by intraclass correlation coefficients.

The inter and intraobserver reproducibility of the EOS^® measures have been respectively of 0.881 and 0.916 and more specifically of 0,997 and 0,997 for femoral length, of 0.996 and 0.997 for tibiae, of 0.999 and 0.999 for limb length, of 0.893 and 0.890 for HKS, of 0.993 and 0.994 for HKA, of 0.892 and 0.914 for femoral offset, of 0.765 and 0.850 for collo-diaphyseal angle.

The inter and intraobserver reproducibility using orthoroentgenograms reached 0.854 and 0.902.

Our results show the EOS^® is a tool allowing reproducible measures. Furthermore 3D EOS^® reconstructions offer better reproducible measures for all parameters that the orthoroentgenograms.

Its use prior to the decision of surgery and during surgery planning for lower limb arthroplasty is for us essential for adjusting surgical procedure accordingly.

Background: Quality control has found an important application in assessing learning curves of trainees and controlling innovative technologies as they are initiated.

Objective: To develop a quantitative and individualized statistical tool that may help trainees and tutors to define when a procedure is adequately learned and supervision may be safely stopped.

Methods: A series of 78 consecutive computer assisted-based navigation total knee replacements in patients with osteoarthritis or rheumatoid arthritis was monitored to control surgical performance. The primary outcome was limb alignment in the frontal plane. The target for alignment was 180° and the standard deviation for limb alignment for this series was 2.35°. Knees implanted with a deviation of more than 3 degrees from the target value were considered as failures. A new statistical tool, the CUSUM for Learning Curve (LC-CUSUM) was used to monitor surgical performance. The LC-CUSUM was developed to test whether a process has reached a predefined level of performance. Therefore, the LC-CUSUM presumes the process is not controlled (not learned) at the start of monitoring and the test will signal when the process can be considered as in-control (learned). For continuous data, two LC-CUSUMs are drawn simultaneously.

Results: The first 20 prostheses were more often implanted in varus alignment. Subsequently, the surgeon tried to correct this problem but tended to implant the prostheses more in valgus alignment (overcorrection). After a few more procedures the surgeon found a balance, and the implants were positioned around the target value with no apparent tendency to favour one side or the other. The positive LC-CUSUM signalled first at the fifth procedure; however, the negative LC-CUSUM had not crossed the lower limit and the surgeon could not be deemed as having achieved the required level of performance. It is not until the 25th procedures that the negative LC-CUSUM crossed the lower boundary. At this point, enough evidence had accumulated to state that the surgeon had reached proficiency. A standard CUSUM was initiated to monitor the process to the end and ensure it would not deviate from the required performance. After the seventy-eighth procedure, monitoring was discontinued.

Conclusion: The LC-CUSUM is an innovative tool that allows quantitative monitoring of individual surgical performance during learning process. It allows stating when a predefined acceptable level of performance is reached.

Background From individual randomized studies it is unclear which of patellar (PT) tendon or hamstring (HS) tendon grafts yields the best functional results after ACL reconstruction. Therefore, we performed a meta-analysis to provide quantitative data to compare PT (control group) to HS (treatment group) grafts after ACL reconstruction with regards to knee function.

Methods We searched computerized databases for randomized controlled trials reporting one of the following outcome related to function: final overall International Knee Documentation Committee (IKDC) score and return to pre-injury level of activity. Studies were abstracted independently by two reviewers. Random effect models were used to pool the data.

Results Fourteen trials (1263 patients) met the inclusion criteria. There was no difference in final overall IKDC and in the number of patients returning to full activity after PT and HS graft reconstruction. Relative risk was 0.90 for final overall IKDC score class A in favor of PT grafts (not significant, P=0.13), and 0.94 for return to pre-injury level of activity in favor of PT grafts (not significant, P=0.28). Quantitative interaction tests on the effect of treatment based on study quality, randomization status, number of strands used, and length of follow-up were not significant. At last follow-up, only 41% and 33% of PT and HS graft reconstructed patients were respectively reported as normal using the final overall IKDC.

Conclusion There was no difference in the final overall IKDC and in the number of patients returning to full activity after HS tendon graft and PT graft reconstructions. It should be emphasized that more than 60% of the patients will not make full recovery after their reconstruction and patients should be informed accordingly.

Purpose of the study: Complex fracture-dislocation of the elbow, and subsequent surgical treatment, is often the source of a stiff joint. The purpose of this study was to assess the efficacy of a therapeutic protocol combining systematic insertion of a dynamic external fixator allowing early mobilization of the elbow with restitution of the radial height and the coronoid process.

Material and methods: This consecutive series of ten patient, six men and four women, mean age 49 years, age range 27–67 years, underwent surgery from 2002 to 2004. Three patients presented a posterior Monteggia fracture (two type IIA, one type IId associated with comminutive fracture of the trochlea), four patients presented a dislocation associated with a Masson 4 fracture of the radial head and two presented inveterated dislocations diagnosed three weeks after the traumatic event. In all, seven patients presented a fracture of the radial head and six a fracture of the coronoid process. For all patients, the operation consisted in stabilization with a dynamic external fixator of the elbow associated or not with restoration of the radial height with a radial head prosthesis (n=4) and reconstitution of the coronoid process (n=6). The lateral ligaments had to be reinserted in four elbows. The comminutive fracture of the rochlea was treated with an iliac crest graft.

Results: One patient died early. One patient presented pin tract infection and four developed heterotopic ossifications. At mean follow-up of twelve months, outcome was excellent in our patients, good in four, fair in one (Mayo clinic classification). All patients had a stable elbow. The mean range of motion was 89° flexion-extension and 145° pronationsupination.

Conclusion: In this series, systematic use of external fixation for complex fracture-dislocation of the elbow joint yielded satisfactory results when the element stabilizing the joint were appropriately restored and when rehabilitation was undertaken early.

Purpose of the study: Computer assisted surgery for total knee arthroplasty is widely used in Europe. The reliability of these systems appears to be very good with bone cuts within 3° of the planned mechanical axis. Nevertheless, the relationship between intraoperative measurements provided by the navigation system and the postoperative gonometry can be used to assess the quality of realignment. The purpose of this work was to determine this relationship.

Material and methods: Thirty-three knees operated on with the Navitrack® system were assessed. Two senior operaters performed all procedures. An Omnia® cemented prosthesis with an ultracongruent fixed plateau was used in all cases. Intraoperative measurements wer made with the definitive prosthesis after cement solidification without stress on the knee. Postoperative gonometry was undertaken when the intraoperative flexion had disappeared six weeks to six months after the operation. Gonometric measurements were made by an independent operator using a computerized system operating on digitalized x-rays. The gonometric protocol had been standardized previously and only the gonometric measurements in compliance with this protocol were retained for analysis. The difference between measurements was analyzed with the t test for paired variables. Search for correlations was also performed.

Results: On average the intraoperative deviation was 0.8±0.8° (3° valgus to 2.4° varus). The postoperative gonometry showed 1.7±1.1° (3.4° valgus to 4.3° varus). The mean difference between the intraoperative axis and the measured postoperative axis was significant (p< 0.0001). There was no significant correlation between intraoperative and postoperative measurements.

Discussion: Computer-assisted navigation systems have their limitations which should be measured. The present findings would demonstrate a significant difference of minimal amplitude between the intraoperative measurement and the postoperative gonometry. Although the clinical pertinence of this difference remains to be demonstrated, it must be kept in mind for safe use of these navigation systems.

Purpose of the study: The limitations of cemented fixation of alumina cups was demonstrated in 1983. At that time, a new metal-backed cup with a titanium ring for screw fixation and a massive alumina insert was introduced. Since the 1990s, the high rat of mobilization of screwed cups, confirmed by midterm studies, has led to the use of more stable cups. The purpose of this study was to follow the clinical and radiological course of screwed cups implanted for more than 20 years, evaluating the real need for surgical revision.

Material and methods: We reviewed independently a consecutive series of 117 prostheses implanted in 105 patients in 1984–1986. All patients had a screwed cup with an alumina insert, a cemented stem, and a 32 mm alumina head. We retained for study patients aged less than 65 years and excluded revision procedures or patients with prior infection. The clinical assessment was made with the Postel-Merle-d’Aubigné (PMA) score: for eight patients, all data were collected during a phone interview. Radiologically, cups were considered to be mobilized if the change in inclination was greater than 6° or the protrusion greater than 5 mm. Actuarial survival was calculated with the Kaplan-Meier method.

Results: Four prostheses in three patients were lost to follow-up before one year. Mean follow-up was 12.62±6.3 years (maximum 21 years). Fourteen patients had died, twelve had had revision and fifteen were lost to follow-up at more than one year. The mean PMA score improved from 11 preoperatively to 17 at last follow-up. Radiographically, 62% of the cups did not present any sign of mobilization. Four percent exhibited a periprosthetic lucent line around the stem. Considering all results together, four outcome categories could be distinguished: A: good clinical result and no radiological change (58.4%); B: good clinical result and presence of a radiological problem (15%); C: poor clinical result and no radiological unchanged; D: poor clinical result and radiological problem (n21.8%) (including revisions). For category B, the cups showed a 20° mobilization. For these patients, revision was not planned because of very satisfactory quality-of-life for age and activity level. All patients in category C had co-morbid conditions explaining the poor clinical result. Category D included revision procedures which had already been performed (73%) and symptomatic cup mobilizations (27%) measured at 13–31°: revision was planned for most of these patients. The 10-year survival was 82%, all revisions considered; at 15 years, the survival was 66.6%, warranting the change in acetabular fixation made in 1989. The decrease in survival from 82.5% at 10 to 66.6% at 15 years shows that this change was indeed necessity.

Conclusion: Good quality-of-life was achieved for 74% of patients at mean follow-up of 13 years. It would be useful to continue following the patients in category B to check whether cup mobilization has been arrested with a certain degree of adaptation. Furthermore, patients who had a revision were free of osteolysiss and the second operation was generally quite uneventful, usually with preservation of the stem and sometimes even the alumina head which was not deteriorated.

Randomised controlled trials represent the gold standard in the evaluation of outcome of treatment. They are needed because differences between treatment effects have been minimised and observational studies may give a biased estimation of the outcome. However, conducting this kind of trial is challenging. Several methodological issues, including patient or surgeon preference, blinding, surgical standardisation, as well as external validity, have to be addressed in order to lower the risk of bias. Specific tools have been developed in order to take into account the specificity of evaluation of the literature on non-pharmacological intervention. A better knowledge of methodological issues will allow the orthopaedic surgeon to conduct more appropriate studies and to better appraise the limits of his intervention.

Purpose: At a time when total knee arthroplasty (TKA) with an ultra-congruent tibial plateau or a mobile plateau are advocated by many, the question is whether TKA with a fixed plateau preserving the posterior cruciate ligament (PCL) should be abandoned. We analysed the results of 500 Wallaby I TKA with preservation of the PCL and presenting asymmetrical and divergent femoral condyles with a fixed, also assymetrical tibial plateau, at mean follow-up of seven years (1–10).

Material and methods: This prospective multicentric study was performed by junior and senior surgeons. Mean patient age was 70.11 years and 91.4% of the patients had primary or secondary degenerative disease. Prior surgery had been performed in 130 knees, mainly for osteotomy (n=40, mostly tibial) and revision of uni-compartmental or total prostheses (n=18). The mean preoperative IKS knee score was 26.11 points, the function score was 29.54. Preoperative alignment was correct for 11.26% of the knees, 27.16% presented > 4° valgus and 61.56% > 3° varus. Nearly all tibial and patellar pieces were cemented. 5.8% of the femoral pieces were not cemented. A prosthesis was implanted on the patella in all knees except four. There were two early infections, one popliteal sciatic paralysis and twelve wound healing problems. General mobilisation under general anaesthesia was performed in 53 knees (10.6%).

Results: Twenty-two patients were not retained for analysis, fifteen lost to follow-up and seven deceased at one year. Among the 478 knees followed for one to ten years, there were six late infections (1.25%), one aseptic bipolar loosening (0.2%), 25 patellar fractures (5.23%) including three which required revision (two cerclage, one prosthesis removal), three periprosthetic femur fractures without effect on the clinical or radiographic outcome, one traumatic tear of the medial collateral ligament, and two secondary tears of the PCL without clinical consequences. There were no revisions for instability, generally considered the most frequent reason for TKA revision. The mean postoperative IKS score was 90.6 points and the function score was 59.7 points basically due to patient age and comorbidity. The eight-year survival (Kaplan-Meier method) was 98.2% (95%CI: 99.4–96.9) irrespective of the reason for revision and 99.2% (95%CI 100–98.4%) if the revision was performed for a mechanical problem. Radiographically, more than 70% of the knees were aligned (between 3° valgus and 2° varus) and more than 90% were between 5° valgus and 5° varus. Although it was difficult to measure radiographically polyethylene wear, there was only one case of > 2 mm wear with osteolysis found in 50 knees selected randomly among the knees with more than seven years follow-up.

Conclusion: This study, like others reported by authors preserving the PCL, show that preservation of the PCL limits the risk of instability, allowing excellent clinical and radiographic outcome without important polyethylene wear, opening perspectives for good long-term results.

Purpose: Surgical techniques must be evaluated before proceeding with widespread use. The evaluation system is usually copied after that used for drugs, relying on randomised trials. This system fails however to assess one dimension, i.e. quality control. The purpose of the present study was to demonstrate the usefulness of an evaluation technique taking into account the capacity to control the quality of a surgical procedure and determine the reliability, reproducibility, and controllability of the technique. This method of evaluation was applied to computer-assisted surgery for total knee arthroplasty.

Material and methods: Computer-assisted surgery based on 3D bone reconstruction was used for 78 knees. The main outcome assessment criterion was the mechanical axis from the centre of the femoral head to the centre of the ankle. The desired alignment was between 3° varus and 3° valgus. Alignments were measured continuously by an independent operator. A Cusum curve was drawn over time and tested after each operation to determine whether the procedure under evaluation could be continued. The same method was applied to the position of the individual femoral and tibial implants setting the limits at two degrees around the perpendicular mechanical axis (AP view).

Results: The mechanical axis was between 3° varus and 3° valgus in 91% of the knees. The continuous evaluation curve showed that the procedure was under control throughout the trial. There was a learning curve that plateaued at 27 knees. Evaluation of the position of the individual implants showed a trend towards femur valgus over time which was compensated by a trend towards tibial varus.

Discussion: Industrial quality control procedures are well established and widely used. The goal of this work was to apply the same quality control methodology to a surgical procedure. Before undertaking a randomised trial this type of evaluation can affirm that the procedure is well controlled and that using an innovating technique under these conditions does not expose patients to undue risks.

Purpose: Total hip arthroplasty after failure of femoral osteotomy raises high risk of complications. Outcome has been controversial. The purpose of this retrospective analysis was to evaluate the difficulties and results.

Material and methods: Between March 1974 and January 1995, 68 patients (82 hips), 51 women and 17 men, mean age 59±11.5 years (32–84) underwent surgery. Initial indications were mainly acetabular and/or femoral dysplasia (n=47 hips) or congenital dislocation (n=21 hips). Mean time between osteotomy and arthroplasty was 13.8±8.4 years (10 months-45 years). We used cemented titanium femoral stems (Ceraver Ostal) with an alumina (n=66) or polyethylene (n=16) cup. An alumina-alumina bearing was used in 67 hips (81%). Functional outcome was assessed with the Postel-Merle-d’Aubligné score. Radiological analysis searched for lucent lines and signs of wear. The actuarial survival was determined.

Results: One patient (1 hip) was lost to follow-up. Thirteen patients (14 hips) died of intercurrent causes. Six hips required revision for aseptic loosening (isolated cup loosening in five and bipolar loosening in one) at 8.5 years on average (4.5–12). There were 22 intraoperative complications (27%) including 18 fractures or femoral stem misalignments and four cases of damage to the acetabular fundus. Other complications included one postoperative dislocation, two sciatic nerve palsies with partial recovery, and one non-union of the greater trochanter. There were no infections. At maximum follow-up (11.8±4.7 years, ragne 5.4–20), the mean functional score was 16.5 (15–18) versus 9.9 (6–14) preoperatively (p< 0.05). There were no femoral lucent lines. A complete lucent line around the cup was observed in eleven hips including six with a massive cemented alumina cup. Considering revision for aseptic loosening as failure, cumulative survival at 12 years was 82% (95%IC 67–96%) for the cup and 98% (92–99.7%) for the femoral stem.

Discussion: These results confirm the high risk of intraoperative complications of total hip arthroplasty performed for failure of femoral osteotomy. Architectural changes expose these patients to technical problems. The survival of the implants appears to be relatively unaffected by the prior procedure but the functional results are slightly less satisfactory then for primary arthroplasties.

Purpose: The aim of this study was to evaluate quality-of-life (QoL) in patients undergoing bilateral hip arthroplasty implanted during the same operation.

Material and methods: Sixty-one patients (28 women and 33 men) underwent surgery between November 1989 and February 2002. Average age was 42±14 years (13–76). Indications were primary osteoarthritis (n=24), secondary osteoarthritis (n=31), aseptic osteonecrosis (n=25) and rheumatoid disease (n=6). The implants (Ceraver Osteal) were cemented (50 stems, 11 cups) or coated with hydroxyapatite (72 stems, 11 cups). An alumina-alumina bearing was used in all cases. The Postel-Merle-d’Aubigné score was noted to assess function. QoL was measured prospectively in 27 patients using the SF-36 and the WOMAC, preoperatively and every three months.

Results: None of the patients were lost to follow-up. Complications included two intraoperative femoral fractures treated by cerclage, one early dislocation, three thromboemoblic events (including one case of pulmonary embolism). Unipolar revision was required for one hip due to aseptic acetabular loosening at 6.5 years. Surgical cleansing was performed in one other hip for infection. Intraoperative blood loss was 1529±451 ml (540–2550). Mean hospital stay was 13±2.5 days (8–22). At mean follow-up of 49±33 months (12–162), the mean function score was 17.8±0.5 (16–18) versus 10±2.7 (3–14) preoperatively (p< 0.05). Clinical outcome was good or excellent in 98% of the hips. There were no radiological signs of wear. A complete lucent line developed around one cup. The quality of life scores improved significantly (p< 0.01) as soon as three months postoperatively for the items ‘social activity’, ‘physical activity’ and ‘pain’, particularly in men p< 0.05).

Discussion: Bilateral hip arthroplasty during the same operative time is not advocated by all authors. It is a difficult surgical situation requiring rigor and skill. The drawbacks include longer operative time, greater blood loss, and in some patients, higher morbidity. This approach however enables treating bilateral disease in one operation, particularly in younger subjects. Use of an alumina-alumina bearing and non-cemented implants is particularly indicated. The results of this series validate the efficacy of this technique which allows rapid improvement in the patients’ quality-of-life.

Purpose: Classical instrument sets for implantation of total knee arthroplasty (TKA) can be perfected. Computer-assisted implantation appears to offer improved technical quality. The purpose of this study was to compare a matched series of TKA implanted with the conventional method and with a computer-assisted navigation system.

Material and methods: Seventy-eight prostheses implanted with a computer-assisted system based on 3D CT-scan reconstruction of the lower limb were matched with 78 prostheses implanted by a highly-trained operator. The knees were matched for gender, aetiology, surgical approach, and axial deviation. There were no significant differences between the groups for these variables. An intramedullary aiming device was used for knees undergoing the conventional procedure. Navitrack(r) was used for the computer-assisted implantations. The same prosthetic system (Wallaby) was used for both series. An independent operator assessed the double-foot stance gonometries. The femorotibial axis was measured as was the individual position of the tibial and femoral pieces.

Results: Axis was within 3° varus and 3° valgus for 92% of the knees operated on with the navigation system. This same range was found for 59% of the conventional procedures. The difference was significant (p< 0.0001). Analysis of the individual femoral and tibial components did not demonstrate any significant difference.

Discussion: Results of TKA are dependent in part on operative technique. The objective is generally achieved with the computer-assisted technique but is not with the conventional technique. Navigation could be useful to achieve successfully short-term objectives. Its contribution to mid-term outcome remains to be demonstrated.

From 1979 to 2002, 131 total hip replacement were performed consecutively in patients less than 30 years of age (13 to 30,7 mean 24;2) in 75 patients (44 in males and 31 in females. Seventy six in 57 patients could have more than 2 years follow-up and will presented hereby. Regarding the type of prosthesis, 59 stem were cemented and 16 cementless. Five different socket were implanted: 6 screw-in metal back: 8 bulky cemented, 23 bulky cementless, 13 metalback press fit with titanium mesh and 26 HA covered.

Underlying diseases were Avascular necrosis in 46, 8 inflammatory disease, 6 after infected articulation, epiphysiolysis in 4 and acetabular fracture in 3.

48 were done primarily, 28 were a revision procedure and 10 had some past history of infection.

Mean follow up was 7,84 years (range 1,13-22,9). One patient (two hips deceased at 1,1 year. One hips was lost to follow-up. 73 had complete clinical and radiological evaluation.

Nine hips were revised from 2,97-18,64 years after the index procedure (mean 8,53). In 7 only the socket was revised, in two both components. Two of these were infected (secondary infection in one). Of the remaining: 45 had no pain, 18 slight uncommon pain, 10 were classified 5 and 8 had some limp.

Radiological evaluation: 56 had no lucent lines nor subsidence, 4 had some radiolucent line none progressive and 1 had a complete lucent line: and is considered as impending failure. In no case osteosysis was documented.

With the exception of socket loosening due to non optimal design of the initial system (bulky alumina cemented or cementless) the overall results are in favor of theis material in young and active patients.