Validation of the in vivo volumetric wear measurement for total knee prostheses in model-based RSA.

Implant failure related to polyethylene wear remains an important issue in total knee arthroplasty. Polyethylene wear is usually assessed in vivo by measuring the remaining insert thickness on X-ray images of the knee. To reflect the amount of wear debris more accurately, a 3-dimensional overlap measurement has been suggested, which is based on implant component models which are matched on calibrated stereo X-ray images using model-based roentgen stereophotogrammatic analysis. The goal of this study was to determine the influence of pose estimation, insert thickness deviation and variation in the femoral-tibial contact location on the accuracy and precision of the measurement using simulations and a phantom experiment. We found that the pose estimation was the largest source of variation. The 95% prediction interval varied between 111 and 283 mm(3), which is approximately 100-200% of the detected volumetric wear. Insert thickness variation resulted in prediction intervals of 74-174 mm(3). Variation of the femoral-tibial contact location in the phantom experiment gave a prediction interval of 40 mm(3). Large differences in the detected wear volume were found for different flexion angles. At most 56% of the true wear volume was detected (129 of 230 mm(3), 30° of flexion). In summary, both the accuracy and precision of the volumetric wear measurement were low. The prediction interval of the volumetric wear measurement is at least as large as the measurement outcome itself. This is an important limitation to the applicability of the volumetric wear measurement in clinical practice and further clinical validation is required.

Simultaneous bilateral total knee arthroplasty. A multicenter feasibility study.

INTRODUCTION: The value and risk of simultaneous total knee arthroplasty (TKA) in patients with bilateral knee arthritis is a subject of debate. HYPOTHESES: The risk of complications following simultaneous bilateral TKA will be increased compared to the rates published in the literature for unilateral TKA, and the clinical and functional outcomes will be poorer in this particular group. MATERIALS AND METHODS: One hundred and twenty-three patients who underwent simultaneous bilateral TKA between 2005 and 2011 in five specialized, high volume centers were evaluated. The files were analyzed retrospectively after a mean 33 months of follow-up. RESULTS: The mean hospital stay was 11 days. Mean blood loss was 4.1g/dL. A postoperative transfusion was performed in 68 patients (55%), with a mean 3.1 units of blood. The mean global IKS score increased from 90 to 150 points. Eighty patients would agree to undergo simultaneous bilateral TKA again (65%), and 70 would recommend this procedure to others (57%). DISCUSSION: The hypothesis was not confirmed: the risk of complications was not increased compared to the generally accepted risk of a unilateral procedure. The risk of complications in this study was very similar to that published in the literature for the same therapeutic strategy. Therefore, there is no solid medical evidence to prevent recommending this strategy. The results of the participating centers suggest that this therapeutic approach should be continued in selected indications. LEVEL OF EVIDENCE: IV, retrospective study.

One-stage bilateral total hip arthroplasty: functional outcomes and complications in 112 patients.

BACKGROUND: Advantages of one-stage bilateral total hip arthroplasty (THA) include a single hospital stay, a shorter rehabilitation time, and decreased management costs per patient. However, concern about a possible increase in the perioperative complication rate has limited the use of this strategy. Here, our objectives were to evaluate morbidity and mortality, as well as functional outcomes, in patients managed with one-stage bilateral THA. HYPOTHESIS: The complication rate after one-stage bilateral THA is not significantly different from that after unilateral THA. MATERIALS AND METHODS: Four French surgical centres participated in a retrospective observational study of patients managed with one-stage bilateral THA. The 112 included patients (55 women) had a mean age of 59 years (range, 22-84) and a mean follow-up of 30 months (6-103). RESULTS: Mean hospital stay length was 10.8 days (6-27), mean operative time was 162 minutes (95-270), and mean haemoglobin levels were 14.3g/dL preoperatively and 10.1g/dL postoperatively. No perioperative deaths were recorded. Deep vein thrombosis occurred in eight (7.1%) patients and pulmonary embolism in six (5.4%). The Merle d'Aubigné score improved from 9.25 ± 2.9 (3-16) preoperatively to 17.5 ± 1 (14-18) at last follow-up. All but three patients (109/112, 97%) said they would choose the same operation again and 102/112 (91%) said they would recommend it to a family member. DISCUSSION: The results of this multicentre retrospective study indicate that one-stage bilateral THA is a valid alternative to two-stage bilateral THA in ASA 1 and 2 patients with a preoperative haemoglobin level of about 14 g/L. The major complication rate was 7.1%, which was slightly higher than after unilateral THA, and the main complications were deep vein thrombosis and pulmonary embolism.

Oral thromboprophylaxis following total hip replacement: the issue of compliance.

INTRODUCTION: Thirty-five to 40 days' thromboprophylaxis is recommended following total hip replacement (THR). Low molecular weight heparin (LMWH) injected by a health professional ensures good compliance. Compliance with recent oral anticoagulants has not been precisely assessed. Oral self-administration, without coagulation monitoring tests, may be a worrying issue in the management of what is a potentially catastrophic adverse event, without prodromal symptoms alerting the patient to the need for regular intake throughout the prescription period. HYPOTHESIS: It was hypothesized that compliance with these new oral anticoagulants is good over the entire treatment period. PATIENTS AND METHOD: The present cohort study prospectively assessed compliance with oral medication (two capsules of dabigatran etexilate [Pradaxa(®)] per day in a single dose at a set time) following THR. An electronic device continuously monitored the day and time of extraction of capsules from the package. All included patients underwent clinical and echo-Doppler examination at day 30±5 after the start of the study. RESULTS: Fifty-six patients were included at their discharge home. Overall compliance was 98.1% (3,188/3246 capsules correctly taken), falling off slightly over time but never below 97.1%. One patient was diagnosed with symptomatic thrombophlebitis 34 days postoperatively, associated with non-compliance at day 11. End of follow-up echo-Doppler found four cases of asymptomatic distal venous thrombosis. There were no hemorrhagic complications. DISCUSSION: The risk of thromboembolic complications diminishes over time, while oral anticoagulants have a wide therapeutic window and relatively long half-life (15-17 hrs). Efficacy was demonstrated, with improved patient comfort and cost-saving. Compliance in the present series was satisfactory. This, however, should not mean that patients not be appropriately informed, as in the present study, so as to improve compliance. LEVEL OF EVIDENCE: Level III, prospective diagnostic.

Total knee arthroplasty three-dimensional kinematic estimation prevision. From a two-dimensional fluoroscopy acquired dynamic model.

INTRODUCTION: To determine six-degree of freedom of total knee arthroplasty kinematics (TKA), optimized matching algorithms for single fluoroscopic image system may be used. Theoretical accuracy of these systems was reported. Nevertheless, all reports were done under idealized laboratory experimental conditions. The aim of this study was to evaluate the "true" accuracy of a flat panel single plane video-fluoroscopy system based on computed-assisted design (CAD) model matching and compare it to TKA kinematics obtained from optoelectronic measurements as gold standard. HYPOTHESIS: The estimation of the error produced by 2D/3D fluoroscopic registration in daily practice is misjudged in most available laboratory reports. MATERIAL AND METHODS: The experimental set-up used a TKA implanted into femoral and tibial cadaver bones. Thirty flexions were simultaneously registered using single plane fluoroscopy and an active optical tracking system. Kinematics registered were compared using the root mean square error (RMS), the concordance correlation coefficient and Bland & Altman plot analysis. RESULTS: The mean range of motion of flexion during the experiment was 106°. The respective RMS for flexion, varus-valgus and internal-external rotation were 0.68, 0.67 and 1.02°. The respective RMS for antero-posterior, medio-lateral and proximo-distal displacement were 1.3, 2.4 and 1.06 mm. Extreme values of the measured error concerning medio-lateral displacement were -5.4 and 22,1mm. DISCUSSIONS: Analysis found some outliners in all degree of freedom with a systematic error and larger standard deviation than already published data. One should make sure that during the experiment the motion of interest is in the in-plane direction. Moreover, this study brings out the true threshold detection of this type of analysis.

Dual mobility hip arthroplasty wear measurement: Experimental accuracy assessment using radiostereometric analysis (RSA).

INTRODUCTION: The use of dual mobility cups is an effective method to prevent dislocations. However, the specific design of these implants can raise the suspicion of increased wear and subsequent periprosthetic osteolysis. HYPOTHESIS: Using radiostereometric analysis (RSA), migration of the femoral head inside the cup of a dual mobility implant can be defined to apprehend polyethylene wear rate. STUDY OBJECTIVES: The study aimed to establish the precision of RSA measurement of femoral head migration in the cup of a dual mobility implant, and its intra- and interobserver variability. MATERIAL AND METHODS: A total hip prosthesis phantom was implanted and placed under weight loading conditions in a simulator. Model-based RSA measurement of implant penetration involved specially machined polyethylene liners with increasing concentric wear (no wear, then 0.25, 0.5 and 0.75mm). Three examiners, blinded to the level of wear, analyzed (10 times) the radiostereometric films of the four liners. There was one experienced, one trained, and one inexperienced examiner. Statistical analysis measured the accuracy, precision, and intra- and interobserver variability by calculating Root Mean Square Error (RMSE), Concordance Correlation Coefficient (CCC), Intra Class correlation Coefficient (ICC), and Bland-Altman plots. RESULTS: Our protocol, that used a simple geometric model rather than the manufacturer's CAD files, showed precision of 0.072mm and accuracy of 0.034mm, comparable with machining tolerances with low variability. Correlation between wear measurement and true value was excellent with a CCC of 0.9772. Intraobserver reproducibility was very good with an ICC of 0.9856, 0.9883 and 0.9842, respectively for examiners 1, 2 and 3. Interobserver reproducibility was excellent with a CCC of 0.9818 between examiners 2 and 1, and 0.9713 between examiners 3 and 1. DISCUSSION: Quantification of wear is indispensable for the surveillance of dual mobility implants. This in vitro study validates our measurement method. Our results, and comparison with other studies using different measurement technologies (RSA, standard radiographs, Martell method) make model-based RSA the reference method for measuring the wear of total hip prostheses in vivo. LEVEL OF EVIDENCE: Level 3. Prospective diagnostic study.

Anatomic basis of ulnar index metacarpal reverse flow vascularized bone graft for index distal bone loss.

Well-known advantages of vascularized bone grafts led us to determine the anatomical basis of a metacarpal vascularized bone graft to find a solution for distal index bone loss. Seventeen adult human hands from fresh cadavers were dissected and analyzed. For each hand, we studied the second dorsal metacarpal artery, the ulnar dorsal proper digital artery of index, and the ulnar palmar proper digital artery of the index. Location, diameters, origins, and anastomoses were observed, and at the end, the vascularised bone graft was raised. The second dorsal metacarpal artery was present in all hands, always arising from the dorsal carpal arch with a 1-mm mean diameter. The ulnar dorsal proper digital artery of index was isolated on all dissections, with a subcutaneous location on the ulno-dorsal side of the proximal phalanx. The mean diameter of ulnar dorsal proper digital artery at the level of index proximal phalanx was 0.4 mm. We found anastomotic branches between the ulnar dorsal and palmar proper digital artery of index at the level of the proximal phalanx which permitted us to elevate a vascularised bone graft. We succeeded in removing the graft in all specimens. Its pivot point was always more distal than the middle of the proximal phalanx. The arc of rotation allowed the graft to reach the distal phalanx in 80% of the cases. This anatomical study has demonstrated the theoretical possibility of a reversed pedicled bone graft taken from the ulnar neck of the second metacarpal. This graft brings the following benefits: (a) the use of a minor vascular axis, (b) a surgical technique with a dorsal approach allowing the elevation and the use of the graft at the same time. It can be used on the index for failures of DIP joint arthrodesis, huge chondroma, or traumatology.

Cemented total hip stem design influence on adaptative cortical thickness and femoral morphology.

INTRODUCTION: Five-year following total hip implantation femur adaptive morphology was compared between two groups differing only in their femoral stem design. MATERIAL AND METHODS: Group 1, recruited prospectively, included 51 Dédicace stems(Stryker-Howmedica) and group 2, retrospectively matched to group 1, comprised 51 Kerboull MK3 stems (Stryker-Howmedica). While MK3 prosthetic system increases in size homogeneously (widening along the whole length as the implant dimension increases), the Dédicace prosthetic system provides various metaphyseal widths for a given diaphyseal size. We opted for primary fixation (press fit according to the "French paradox") prior to cementing in both cases, despite the risk of discontinuity in the cement mantle. The homogeneous dimensioning of the MK3 stem enables distal primary fixation, whereas the Dédicace range allows differentiated adaptation to diaphyseal length and metaphyseal caliber. The following parameters were measured and calculated: Noble index, femoral cortical thickness score of Barnett and Nordindiaphyseal filling and stress-shielding at three levels around the stem. RESULTS: Bone-remodeling, assessed on X-ray, was without clinical impact, whether it took the form of spongialization or stress-shielding. The sole factor tending to induce stress-shielding was a high degree of canal filling by the distal third of the stem, more frequently encountered with the MK3 model. Metaphyseal filling was equivalent with all stems. In the matched series on the contralateral healthy side, femoral spongialization was comparable. LEVEL OF PROOF: Level III; case/control study.

[Antithrombotic prophylaxis after THA and TKA: the surgeon's point of view]. / Prophylaxie antithrombotique après PTH et PTG : le point de vue du chirurgien.

Total hip arthroplasty (THA) and total knee arthroplasty (PTG) are surgical interventions aiming at functional improvement. They therefore cannot accommodate any "collateral damage" produced, notably by symptomatic thromboembolic events (STE). Use of the necessary thromboprophylaxis has made STEs rare (<3% after THA and 2% after TKA). Pulmonary embolism (PE) is exceptional (0.3%) and only accounts for 15% of the deaths occurring in the 1st postoperative month. However, atherothrombotic disease is significantly associated with thromboembolic venous disease. The causes of STEs are mechanical, directly related to surgical maneuvers, but also biological (familial or acquired thrombophilia, hypercoagulability, particularly associated with hip surgery). Delayed resumption of walking, which promotes venous stasis, has been improved by modern pain management techniques. There is consensus on the need to prolong thromboprophylaxis after THA, but it is more controversial after TKA and depends on the added risk factors. In France, prolonged prevention is widespread. The relatively low STE rate should be put into perspective with the risk of hemorrhage. The surgeon should be particularly attentive to the risk of bleeding at the operative site because it generates a risk of sepsis, and a risk of stiffness for TKA. The risk of hemorrhage essentially results from the misuse of all the anticoagulants, particularly observed with the anti-vitamin K medications because their use is more restricted. The risk of hemorrhage has become quite comparable to the risk of thromboembolism with prophylaxis. To prevent this event, the prescriber must know the characteristics of each drug : Tmax, half-life, mode of elimination, as well as the risk of accumulation in the patient receiving such treatment (creatinine clearance). Currently, the thrombohemorrhagic risk for each patient must be assessed. Per os treatment with Dabigatran etexilate is highly advantageous because it is easy to use, there is no thrombopenia induced by heparin, and there is no need for complementary monitoring exams, thus reducing costs. Efficacy in terms of prevention and hemorrhagic risk, demonstrated in phase II studies, must be confirmed by widespread used in real-life conditions.

[Survival of the cementless Bousquet dual mobility cup: Minimum 15-year follow-up of 437 total hip arthroplasties]. / Survie à 16,5 ans de recul moyen de la cupule, double mobilité, non scellée de Bousquet dans l'arthroplastie totale de hanche. Série historique de 437 hanches.

PURPOSE OF THE STUDY: The purpose of this study was to evaluate the long-term results of a retrospective series of primary arthroplasty with a cementless dual mobility socket and a cemented Charnley type femoral component. MATERIAL AND METHODS: This study included 437 hip replacements performed between 1984 and 1990, in 388 patients. The Bousquet's acetabular component, an original concept of cementless dual mobility socket has been used, associated with a cemented Charnley type femoral component. A clinical and radiologic analysis was done. RESULTS: The outcome is known for 345 hips (79%): 164 alive without revision at a mean of 16,5 years follow-up, 137 died without revision and 44 failures. Ninety-two (21%) were lost at follow-up. According to Kaplan-Meier analysis, the 5-year survival rate, was 84,4%+/-4,5 with revision for any reason (infection, dislocation, osteolysis...) for end point. Revision, for aseptic loosening of femoral or acetabular component, was performed in 30 hips (6,8%). Five dislocations occurred and were revised: two early related to technical errors and three after 10 years or more of follow-up. The young age of the patients at the time of the index surgery was correlated with higher rate of aseptic loosening. DISCUSSION: The prevalence of revision for dislocation is very low in our series. This concept does not avoid wear, osteolysis and aseptic loosening, especially in young active patients but the long-term stability is confirmed. We recommend this type of prosthesis for patients over 70 years and for younger patients with high risk of dislocation Q.

[Hip dysplasia and misalignment in patients aged 20-50 years]. / Dysplasie et conflits de hanche de 20 à 50 ans.

Anterior hip pain in young adult (20 to 50) has two main causes: secondary osteo-arthritis on development dysplasia of the hip, and femoro-acetabular impigement (FAI). This symposium had two parts: the first one analyses long-term results of non-prosthetic surgery (283 osteotomies and shelfs at 15 years FU). The second part concerned the different syndromes with acute anterior hip pain, especially due to FAI and to labral tears.In hip dysplasia, 56 shelf operations, 100 proximal femoral varus osteotomies associated or not with a shelf arthroplasty,and 127 Chiari osteotomies were examined with 10 years minimum follow-up. Only 15% of patients were lost at follow-up before 10 years and average follow-up was 15 years. Results were considered as satisfactory when the Merle d'Aubigne rating was 15/18 or more. The 3 main factors of good prognosis were: a complete correction of both femoral and acetabular dysplasia; age at operation under 40; a moderate arthritis (grade I or II according to De Mourgues and Patte). In single acetabular dysplasia with 3 favorable prognosis factors(no coxa valga, age under 40, arthritis 1 or 2), 85% good results were achieved at 15 years. When patients were over 40 at operation, or in arthritis grade over 2, only 55% of good results were observed. Varus osteotomies, associated or not with shelf arthroplasties, achieved also 85% goods results at 15 years when the 3 favorable prognosis factors were present. Similar good results were also obtained by Chiari osteotomy, but this operation was associated with 12% complications, and more that 25% of lasting limping. Therefore, with 85% good results at 15 years (and often over 20 years), non prosthetic surgery performed at 30-35 years, achieved better functional results than total hip arthroplasty, longer lasting, and not jeopardizing any further possibility of prosthetic surgery.As concerns acute anterior pain of the hip, the clinical and imaging patterns of the different syndromes have been precised: femoro-acetabular impigement by cam (or by pincer), labral tears in hip dysplasia. There were distinguished from the other secondary impigements, for example by acetabular malposition due to pelvis anteflexion or by other hip diseases: overuse arthritis, coxa retrorsa, etc. Several examples of typical syndromes were presented to support the recommended imaging techniques. The results of the speakers with different surgical treatments were reported as well as concerns open surgery than arthroscopic treatment (60 cases).

Venous thromboembolism and mortality after hip fracture surgery: the ESCORTE study.

BACKGROUND: Recent changes in the management of hip fracture surgery patients may have modified the epidemiology of postoperative complications. OBJECTIVES: We performed an observational study of a cohort of patients undergoing hip fracture surgery to update the epidemiological data on this population. The primary study outcome was the incidence of confirmed symptomatic venous thromboembolism (VTE) [defined as deep vein thrombosis, pulmonary embolism (PE), or both] at 3 months. Overall mortality at 1, 3 and 6 months was also evaluated. PATIENTS/METHODS: Consecutive patients aged at least 18 years hospitalized in French public or private hospitals (531 centers) undergoing hip fracture surgery were recruited prospectively during 2 months in 2002 and a follow-up at 6 months. Predictive factors for VTE at 3 months and for death at 6 months were also analyzed. RESULTS: Data from 6860 (97.3%) of the 7019 recruited patients were included in the analysis. The median age was 82 years. Low molecular weight heparins were administered perioperatively in 97.6% of patients; 69.5% received this treatment for at least 4 weeks. The actuarial rate of confirmed symptomatic VTE at 3 months was 1.34% (85 events, 95% CI: 1.04-1.64). There were 16 PEs (actuarial rate: 0.25%), three of which were fatal. Overall, 1006 (14.7%) patients were dead at 6 months. Cardiovascular disease was the most frequent cause of death (270 patients; 26.8%). CONCLUSIONS: The current rate of postoperative VTE is low, but overall mortality remains high. Indeed, hip fracture patients belong to a vulnerable group of old people with comorbid diseases and a high risk of postoperative morbidity and mortality. An interdisciplinary approach could be the challenge to improve short and long-term outcome.

[Arthroscopic knee arthrodesis: 4 cases]. / Arthrodèse du genou sous arthroscopie. A propos de 4 cas.

PURPOSE OF THE STUDY: Arthroscopic arthrodesis of the knee joint is an alternative to classical surgery, which retains a few exceptional indications. We report the first four cases of our experience, describing the technical modalities and indications. MATERIAL AND METHODS: The four patients had undergone multiple operations for severe trauma. All four had persistent severe pain with a very limited walking distance. Before the procedure, the IKS score ranged from 11 to 44 and the mean function score was 20 to 45 points. Arthroscopic arthrodesis was proposed after several consultations and took into account the young age of the patient and a positive brace test. The successive arthroscopic times were: exploration and adherence release, complete extramural meniscectomy, joint surface avivement. Traction was not necessary. Careful avivement spared the anatomic curvatures of the condyles and slightly scraped out the plateaus. Finally, the arthrodesis was fixed in correct position under fluoroscopy using a single tube external fixator. The fixation was maintained until fusion (satisfactory x-ray and no pain). RESULTS: A drain was inserted only for the first patient. There were no cutaneous complications. Patients were discharged after 3 days on the average with immediate simulated weight bearing using two crutches. The external fixator was dynamized at two months (mean) and removed at five months. The functional gain was considerable in four patients, assessed at two years, with a mean IKS score of 75 and a mean function score of 80. The four patients walked without crutches and without pain. Single leg stance was stable. Final leg shortening was 1 to 2 cm. CONCLUSION: The arthroscopic approach provides several benefits: uneventful postoperative period, little bleeding, no cutaneous complications, shorter hospital stay. The time to fusion appears to be shorter than with classical techniques, but cannot be demonstrated clearly because of the diversity of the series reported in the literature. Arthroscopic arthrodesis does not require any special instruments, but does require surgical skill and a lengthy procedure. When arthrodesis is required the arthroscopic procedure is indicated for minimally deformed knees without major loss of bone stock.

[Patellar reconstruction during total knee arthroplasty after previous patellectomy]. / Reconstruction patellaire au cours d'une arthroplastie totale sur genou patellectomisé

PURPOSE OF THE STUDY: In order to limit the consequences of prior total patellectomy on knee function after total knee arthroplasty, we propose an original technique using an en bloc patellar graft to reconstruct the quadriceps lever arm. The purpose of this work was to describe the technique and present preliminary results obtained in seven patients. PATIENTS AND METHODS: Seven en bloc patellar grafts were performed in seven patients (6 women and 1 man) during total knee arthroplasty procedures for femorotibial degenerative joint disease after prior patellectectomy (mean 13 years before arthroplasty, range 5-20 years). We implanted three posterior stabilized prostheses, one ultracongruent prosthesis, two prostheses preserving the posterior cruciate ligament, and one bi-cruciate prosthesis. The patella was reconstructed with an autologous bone graft fashioned from the tibial plateau in six cases, and with a homologous graft fashioned from a bone-bank femoral head in one. Transosseous sutures were used to fix the graft to the extensor system. A polyethylene button was cemented on five of the grafts. RESULTS: Active extension was defective in five knees prior to the patellar graft and in only one knee after patellar reconstruction. The IKS knee score improved from 41 points (range 35-45) before surgery to 78 points (range 55-95) after grafting and the IKS function score from 35 (range 5-50) to 72 (range 40-100). Four of the seven grafts were removed (eight weeks to five years after implantation, mean two years) mainly due to failure of fixation leading to progressive migration. Follow-up varied from eight weeks to six years. Mean follow-up for the three grafts still in place was 4.6 years (4-6 years). After removing the patellar graft (4 knees) the IKS knee score decreased to 68 points (20-95) and the IKS function score to 62 points (30-100). Lack of active extension reappeared in three of the knees after removing the patellar graft but was not observed in the three knees with the patellar graft in place (and flexion was at least 110 degrees ). Microradiography of the patellar graft explanted after two years revealed peripheral corticalization with areas of living bone tissue seen on the pathology specimens. Inversely, the autografts explanted at eight weeks and at five years exhibited bone necrosis. CONCLUSION: This preliminary study shows that patellar autograft can improve the performance of total knee arthroplasty on patellectomized knees. The fixation technique must be improved using transosseous transverse sutures in addition to peripheral sutures in order to limit secondary migration of the graft. A patellar autograft fixed into the extensor system can remain viable two years after implantation. This technique can be proposed when total knee arthroplasty is indicated for a patellectomized knee, particularly in patients with lack of active extension.

[Patellar tendon-bone autograft reconstruction of the anterior cruciate ligament for advanced-stage chronic anterior laxity: is an extra-articular plasty necessary? A prospective randomized study of 100 patients with five year follow-up]. / Intérêt d'une plastie extra-articulaire dans le traitement des laxités antérieures chroniques du genou par une autogreffe de tendon rotulien. Etude prospective randomisée d'une série de 100 cas avec 5 ans de recul.

PURPOSE OF THE STUDY: This prospective randomized study was conducted to analyze the anatomic and functional impact of an extra-articular lateral plasty associated with patellar tendon-bone autograft in anterior cruciate ligament reconstruction. MATERIAL AND METHODS: A consecutive series of 100 patients with grade II (Noyes classification) chronic anterior laxity confirmed on stress x-rays were included in the study. All patients had a positive Trillat-Lachman test, a direct anterior drawer at 90 degrees flexion confirmed on the lateral x-ray, and an instrumental differential laxity greater than 5 mm (manual arthrometry, Medmetric KT1000). Mean patient age was 27 years (range 16-29 years) and time from the accident to ligamentoplasty was 29 months (range 3-156 months). In the operating theater, the patients were assigned at random to two groups. Group 1 (50 patients) underwent arthroscopic free patellar tendon-bone autograft reconstruction of the anterior cruciate ligament. In the second group (50 patients) the same reconstruction was further supported by a lateral extra-articular plasty using the quadriceps tendon. All patients were followed prospectively. At 58 months follow-up (none of the patients were lost to follow-up) residual laxity (Medmetric KT1000) was noted and functional outcome was assessed using the IKDC criteria. The Aglietti method was used to assess the position of the drill holes. RESULTS: The two groups were strictly identical at inclusion. At last follow-up, the statistical analysis did not reveal any significant difference between the groups for subjective outcome, joint motion, instrumental residual laxity, meniscal stock, or radiological changes. The overall IKDC score was A or B in 80% of the patients in group 1 and 88% of the patients in group 2. Delay to resumed sports activities (about 12 months) was also equivalent in the two groups with a trend towards lower intensity and sports producing less stress on the knee. A minimally positive pivot test with no effect on stability was observed in 4 patients in group 1 (intra-articular plasty alone) and in 2 patients in group 2 (intra- and extra-articular plasty). 16% of the insufficient results (IKDC C and D) were related to repeated tears (n=8, 6 patients in group 1 and 2 patients in group 2, p=0.268), and failure (n=8, 4 in each group) due to defective motion and pain. Repeated tears were strongly correlated with incorrect drill hole position in the tibia (p=0.01) or femur (p=0.024). Despite the stabilization, radiological remodeling was observed in 31% of the patients in both groups. DISCUSSION: The results in this consecutive series of patients demonstrated the good results obtained with intra-articular ligamentoplasy using the mid third of the patellar tendon. The rate of repeated tears or minimally positive pivot tests was higher in group 1 with intra-articular plasty alone but did not reach statistical significance and was generally related to a technical error in positioning the autograft, making it difficult to draw any conclusion concerning the anatomic superiority of mixed plasty. CONCLUSION: At the current follow-up of 5 years, this study was unable to demonstrate any advantage of systematic conjunction of an extra-articular lateral support for advanced chronic anterior laxity of the knee treated by a free patellar tendon graft.

[Arthroscopic tibio-talar arthrodesis: limitations and indications in 20 patients]. / Arthrodèse tibio-talienne sous contrôle arthroscopique: limites et indications.

PURPOSE OF THE STUDY: The purpose of this study was to present the clinical and radiological outcome in 20 patients who underwent arthroscopic tibiotalar arthrodesis. MATERIAL AND METHODS: Between 1993 and 1999, twenty patients (twelve men and eight women) underwent arthroscopic tibiotalar arthrodesis and have been followed for a minimum of one year. Mean age at the time of the procedure was 55 years. The left side was treated in eleven patients and the right in nine. There were a variety of underlying conditions, but post-traumatic osetoarthritis predominated (ten patients); five patients had primary degenerative disease, three had "neurological" ankles, one had polyarthrtis and one necrosis of the talus. Three patients had previously undergone a double fusion and one other had had a subtalar arthrodesis. The preoperative Broquin score, which accounts for pain and walking distance, was 3.3 points on a scale of 8. The walking distance was less than 1000 meters for most of the patients. Radiographically, ten feet presented a frontal valgus deformity (mean 5.3 degrees); three had a varus deformity (mean 8 degrees) and seven were well-aligned. In the sagittal plane, there were ten cases of pes equin, including five greater than 10 degrees. The mean tibiopedal angle was 94+/-8 degrees. RESULTS: Mean hospital stay was four days. There were four complications: two superficial infections that resolved and two cases of reflex dystrophy. First-intention fusion was achieved in 17 patients (85%) after a mean 3.7 months (range 3-10 months). Three patients presented a non-union, two undergoing successful open surgery and one preferring to decline surgery on a well tolerated non-fused ankle. At last follow-up, fifteen patients were satisfied or very satisfied and five were dissatisfied. Pain was minimal or absent in 67% of the cases. The Duquennoy score was good or very good in eleven patients, fair in eight, and poor in one. Radiographical data were available for nineteen patients: four had a correct alignment in the frontal plane, eight exhibited valgus (mean 4 degrees), and seven varus (mean 8 degrees). In the sagittal plane, fifteen feet exhibited pes equin (mean 7 degrees), three a neutral position and one pes talus (4 degrees). The mean tibiopedal angle at last follow-up was 95.4 degrees. CONCLUSION: Although arthroscopic tibiotalar arthrodesis cannot improve the rate and delay to fusion in comparison with open surgery, it does reduce morbidity and the length of the hospital stay. We reserve the arthroscopic approach for ankles which are correctly or nearly correctly aligned without loss of bone stock, especially if there are local or general risk factors for open surgery.