Purpose of the study: Several authors have focused attention on the kinematics of total knee arthroplasty. In vitro studies have shown the influence of prosthetic kinematics on wear of the tibial insert. In vivo, investigations are limited for this important parameter. We propose computer algorithm which gives a linear assessment of femur penetration into the tibial insert. The purpose of this work was to test this measurement by radiostereometric analysis (RSA) on pre-worn prosthesis models.

Material and methods: A resin plateau was manufactured with four Triatlhon posterior stabilized inserts. Three of these inserts were pre-worn on the medial glenoid; wear varied from 0.8 to 1.2 mm. The wear pattern was controlled by a computer program in order to localize it on a posteromedial gliding band posteriorly to the posterior stabilization implant. A femoral component was implanted on dry bone and loaded on a simulator. RSA images were obtained for each of the plateau. Five series of images were obtained from 0 to 40° flexion. The measurement method consisted in defined a perfect middle plane based on the analysis of tantalum beads embedded in the resin plateau, the to define the point the closest to this plane belonging to the medial condyle. The norm of the normal vector for this plane passing through the lowest point of the femur was the reference. The difference of the norms of the vectors constructed from the healthy plateau and the worn plateaus was defined as penetration of the femur into the tibia insert. The rood mean square (RMS) method was used to measure intraobserver variability and the interclass coefficient of correlation (ICC) was determined.

Results and Discussion: Our results were encouraging. 0.8/to 1.12 mm wear was detected with very good accuracy. The data spread was however wide, irrespective of the wear value. The images in flexion of this model provided the most reliable readings. This study is the first offering an approach to wear measurement in vivo. The data spread should be improved by fine tuning the experimental model and the pre-wear pattern.

Conclusion: In vivo measurement of TKA wear remains a challenge in clinical medicine. Our work demonstrate the feasibility of using RSA.

Purpose of the study: The concept introduced by Gilles Bousquet is an effective arm against dislocation of total hip arthroplasty (THA), as has been demonstrated in clinical series with a long follow-up. There remain certain questions concerning wear of dual mobility cups. We propose a radiostereometrical analysis (RSA) of femoral head migration in this type of implant. Our objective was to establish an accurate measurement and determine the intra- and interobserver variabilities.

Material and methods: A THA model was implanted and loaded with a simulator. Penetration of the implants was measured using a specially designed polyethylene insert with increasingly concentric wear (from 0, 0.25, 0.5 to 0.75 mm). Three investigators analysed (7 times in a double-blind protocol) the RSA images of these four inserts. The investigators were an expert (I), well-trained (II), naive (III). The accuracy of the measurement as well as the intra- and interobserver variabilities were determined using the root mean square (RMS) method, the interclass coefficient of correlation (ICC), the Bland and Altman analyses, and weighted Kappa analysis.

Results: Regarding accuracy, the RMS was 0.0388 [CI95: 0.02266–0.05564]. The mean error for preworn inserts was respectively 0.022mm (for 0.25mm prewear), 0.59mm (for 0.5mm), and 0.022mm (for 0.75mm). The intra-observer ICC was 0.9714 [0.9028–0.9918] for investigator I. The interobserver ICCs between investigators I and II and between I and III were respectively 0.943 and 0.968. The weighted kappa coefficients between I and II and between I and III were 0.827 and 0.849. The Bland and Altman analysis confirmed these results.

Discussion: Several RSA protocols could be designed to measure wear of the dual mobility cup. We chose detection of the wear pattern instead of the tantalum beads method. Our protocol, using a simple geometric model and not the manufacturers CAD files, showed an accuracy comparable with manufacturing tolerances with low variability.

Conclusion: This study validated our measurement method, a prerequisite for a randomized multicentric study which has been initiated to compare, by RSA, penetration of the head into the double mobility insert versus a fixed insert.

Purpose of the study: Comprehension of total knee arthroplasty (TKA) kinematics is primordial for improving the functional outcome and longevity of these prostheses. Several methods are available for evaluating knee kinematics. The purpose of this study was to determine the accuracy of the 2D fluoroscopic method in vitro, taking optoelectronic analysis as the gold standard.

Material and methods: In order to compare these two techniques, a posterior stabilised prosthesis was implanted on dry bones. The lateral ligaments were modellised with two elastic bands. Thirty flexion movements were imposed consecutively. The kinematics of this prosthetic model were recorded simultaneously using the fluoroscope and a computer-assisted surgery system. The technique used for the fluoroscopic analysis was based on the detection of the contours and projective geometry algorithms. The statistical analysis measured differences and correlations between the two systems using the root mean square (RMS) method and interclass coefficients of correlation (ICC) in addition to Bland and Altman analyses.

Results: Three hundred thirty six relative implant positions were analysed for 30 flexions from −8 to 132 degrees. The objective RMS were to the order of one degree for flexion, varus and tibia rotation. Conversely, there was a difference of 2.43±3.17 mm for the mediolateral distance (ML). Similarly the ICC were to the order of 0.9 for the six degrees of freedom of the model with the exception of ML displacement where the ICC was 0.106. These analyses were confirmed by the Bland and Altman analysis which revealed an underestimation of the ML distance by the fluoroscopic method in greatest internal rotation.

Discussion: This study is the first using a realistic model to evaluate the kinematic data provided by 2D fluoroscopy in comparison with conventional navigation data. The results show a good agreement between the two techniques and a small difference in measures excepting for the ML plane. The results are less satisfactory than those reported in the literature where data were obtained from computer simulations.

Conclusion: 2D fluoroscopy of the TKA kinematics provides precise data. Nevertheless, the limits and inaccuracies of this technique should be recognized. This study is a prerequisite for in vivo 2D fluoroscopy.

Results and longevity of total knee arthroplasty depend on the correction of axis of the lower limb and the stability of the prosthesis. Faithful to the principle of dependent cuts, our goal was to obtain two equal correlated, rectangular extension and flexion gaps using a ligament balancing tensor called CORES^® (Stryker^®).

Material and Methods: We retrospectively studied the results of a continuous series of 122 total knee arthroplasties (Jade^®, Stryker^®) implanted by only one operator, between December 1994 and 1997. The mean follow-up is 9,5 years. Tibial plateaus were slip and fixed, with or without conservation of the posterior cruciate ligament. Mean patient age at implantation was 71,2 years. 94% had osteoarthritis and 6% rheumatoid disease. The mean preoperative IKS score was 23,4 and the IKS function score was 42,6. 16% of knees were aligned normally, according to the IKS criteria, 24% presented valgus > 4°, and 60% presented varus > 3°. Patella was centred (AA’ distance < 3mm) in 65% of cases and not tilted (alpha angle< 5°) in 41% of cases. There were 22% antero-medial and 78% antero-lateral with ATT eversion approaches. All tibial and femoral components were cemented. Resurfacing patella was not the rule (5%). Clinical outcome was assessed with the IKS score and radiological outcome with the IKS criteria.

Results: There were no early complications. At follow up, the mean IKS knee score was 90 points with mean motion 109°. Mean IKS function was 85 points. 82% of the knees were aligned (HKA angle between 177° and 183°), 7% in varus, and 11% in valgus. Patella position was centered in 80% of cases, and tilted in 8%. No patellar dislocation was observed. Radiolucent lines were observed in 20% of the tibial components, without aseptic loosening. 3% of the femoral component presented radiolucent line, and one was symptomatic. Four TKA were removed at ten and eleven years, corresponding to three deep haematogenous infections and one aseptic loosening (a young man with haemophilic arthritis). Arthroplasty survival rate was 95% at 9,5 years (Kaplan-Meier method), considering all reasons for removal, and 99,4% for removal for aseptic loosening with 95% confidence interval.

Discussion: Since a well-balanced distribution of medial and lateral contact forces avoids overload of one compartment and thus premature wear, knee imbalance assessment is a key point in TKA. This method allows ongoing intraoperative assessment of the angular and rotational correction, bone defect, as well as bone resection levels.

Conclusion: To our knowledge, our study report the first results at 9,5 years of a TKA based on dependent femoral cuts using a ligament tensor. This confirms the durability and longevity of this model of prosthesis, and the accuracy of the method.

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

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

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

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

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

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

Purpose of the study: The objective of this retrospective analysis was to examine the functional and radiographic results of 33 resvisions for femoral implants using a long locked stem inserted without cement and coated with hydroxyapatite.

Material and methods: Mean follow-up was two years for 33 patient who underwent revison total hip arthroplasty (rTHA) with implantation of a press-fit long locked hydroxyapatite coated femoral stem (Aura or Linea) between 2000 and 2004. The explanted prosthesis was cemented in 23 cases. The reason for revision was femoral loosentng for 60%, femoral fracture for five pateints, and infection for two. According to the SOFCOT 1999 criteria, ten patients had bone defects score grade III or IV. Femorotomy was performed in 21 cases. Patients were reviewed clinically and radiologically. Function was assessed with the Postel-Merle-d’Aubligné (PMA) score and radiographic analysis determined the quality of osteointegration of the implants and the restitution of bone stock.

Results: There were six early complications (one death, one disloction with sciatic paralysis), and six late complications, mainly related to defective locking. The PMA score was less than 3 for only three patients. Twenty-six patients were satisfied or very satisfied and seven patients reported thigh pain which was generally moderate. The locking was released for five prostheses because of failure or pain (relief observed in three cases). Migration was noted in three cases, illustrating their non-integration. For 15 patients, corticalisation around the lower part of the prosthesis suggested implant mobility. This image was observed in all patients who complained of thigh pain (p=0.057). There was a significant increase in the cortical index, reflecting progression of the bone stock favoring the internal cortex.

Conclusion: This type of implant has provided a solution for the difficult problems of explantation and reimplantation of THA. These prostheses provide satisfactory short-term results and a significant improvement in bone stock. There remains the problem of osteointegration of certain implants. Technical factors can contribute to improved clinical results.

Purpose of the study: Free patellar tendon plasty is the most common technique for repairing anterior knee laxity. Functional outcome can be compromised by invalidating knee pain. The purpose of this prospective randomized study was to compare the outcome of plasty procedures using hamstring tendon versus patellar tendon autografts.

Material and methods: From May 1998 through May 2001, 100 patients presenting an isolated grade I anterior cruciate ligament (ACL) tear were included. Exclusion criteria were: history of fracture, advanced-stage laxity (grade II or greater), and contralateral ACL tear. Randomization was performed in the operative theater using the closed envelop method. Two groups of 50 patients were designated: group A: arthroscopic free bone-tendon-bone patellar autograft; group B: arthroscopic free four-strand hamstring autograft. Two metallic interference screws were used for fixation in both groups. The two groups were comparable for demographic features and clinical, radiological, and instrumental laxity variables recorded before surgery. The position of the tunnels was noted according to Aglietti and was the same in the two groups. The same rehabilitation protocol in a dedicated center was used for both groups. All patients (none lost to follow-up) were assess using the IKDC 1993 criteria with objective instrumental measurement of residual laxity. The level of significance was set at 5%.

Results: There was no significant difference between the groups regarding: resumption of sports activity (level and delay), joint motion, ligament examination, the overall IKDC score, and radiological findings ate mean 40±13 months (range 13–69 months) follow-up. Pain at the harvesting site was observed in 34.78% of patients in group A at six months and in 39.5% of those in group B. Conversely, anterior pain was found in 8.5% of patients in group B at six months and 6.6% at one year (p< 0.05). This statistically significant difference disappeared at two years. Instrumental differential laxity was 0.57±1.3 mm in group A and 1.22±1.9 mm in group B (p=0.56, but with power < 80%). There were two cases of repeated traumatic tears in each group. Repeated meniscectomy was performed in one patient in group A and in three in group B (p=0.3074).

Conclusion: The results at 40 months follow-up of this prospective randomized study with no patients lost to follow-up confirmed the minimal morbidity observed at the harvesting site for hamstring plasty. There was no significant difference between the transplants (patellar tendon, hamstring). Anterior pain with the patellar tendon plasty attenuated after two years. Residual laxity was greater when using the hamstring method.

Purpose of the study: The purpose of this retrospective study was to analyze outome at more than one year of 33 anterior cruciate ligament (ACL) ligmanetoplasties performed in subjects aged over 50 years.

Material and methods: Between 1997 and 2002, arthroscopic ACL ligmantoplasty with a free graft was performed for 33 patients aged 50–67 years (mean 55.2 years). All patients were reviewed clinically and radiologically at least one year after surgery (mean follow-up 31 months, range 12–60 months). IKDC criteria and manual KT-1000 measurements were recorded. All subjects were classified C or D before the operation (IKCD 93 criteria). Plain x-rays were considered normal for 21 patients (63.5%) and eight (24%) presented remodeling of the medial femorotibial compartment or the intercondylar eminences. Four knees (12.5%) presented an asymptomatic narrowing of the medial femorotibial space (< 50%). In all patients, the indication for surgery was instability for daily life and/or sports activities, even for patients presenting an asymptomatic narrowing. An inter-articular patellar tendon graft, using two independent tunnels was performed for 29 patients. A hamstring plasty was performed for the others. Mean time from injury to surgery was 18 months. There were 15 lesions of the medial meniscus (45.5%). Six lesions were not repaired because they were considered stable. The lateral meniscus was involved less often (n=11 lesions). The lateral meniscal stock was preserved in nine knees. The rehabilitation protocol was the same as used for ligamentoplasty in young sportive patients.

Results: There were no intraoperative complications. Supplementary fixation of the tibia was required for three knees. All patients resumed their sports activities at the same level. The overall IKDS score was A for eight patients, B for 19 and C for six. For the patients in class C, the poor IKDC score resulted from persistent pain, generally present before the operation. Joint motion was preserved in 30 patients. IKDC laxity was A or B in all patients. At last follow-up, there was no radiological worsening and no meniscal injury left unrepaired required secondary treatment.

Conclusion: The operative technique was joint instability for daily life activities. Stability was improved in all patients, but the surgery did not improve pain relief. Age greater than 50 years is not a contraindication for arthroscopic reconstruction of the central pivot for chronic anterior instability. Fixation of the implant must be precise. The indication for surgery depends on the severity of the instability for daily life activities in a motivated patient.

Purpose of the study: The issue of which graft to choose for anterior cruciate ligament (ACL) reconstruction is still a matter of debate. An analysis of the literature reveals the difficulty encountered when performing comparative trials. It is also difficult to demonstrate significant differences with results obtained with an insufficient number of patients. We propose here a meta-analysis in order to combine the results obtained with different comparative studies.

Material and methods: The literature search (Medline 1990–2005) was based on the following selection criteria: ACL reconstruction, patellar tendon (PT), gracilis and semitendinous (four-strand hamstring) reconstruction and comparative prospective study. Studies were retained with: > 30 patients per group, minimum follow-up 24 months, IKDC score. Evaluation criteria retained were: anterior pain, resumed activity, IKDC score, differential laxity. The relative risk (RR) statistical method with 95% confidence interval (CI) was applied. Means were calculated and the chi-square and z-tests were applied.

Results: Thirteen studies satisfied our inclusion criteria. These studies had included more than 1300 transplants. Mean rate of anterior pain was 23.2% with PR and 17.3% with hamstring reconstructions. The RR was 0.73 with a CI different from 1. The difference was significant. Resumption of sports activities at the same level, subjective assessment, number of failures, and overall IKDC score were not statistically different between the two types of transplants. The IKDC laxity score was not different but the residual maximal manual differential laxity was greater in the hamstring patients than in the patellar patients in 80% of the cases.

Conclusion: At the observed follow-up, free grafting with a four-strand hamstring tendon or a patellar tendon is an effective method for reconstruction of the ACL. Anterior pain is more frequent with the patellar tendon method and residual laxity is greater with the hamstring method. The long-term outcome will determine whether the residual laxity observed with the hamstring graft has a deleterious effect on the meniscocartilaginous structures. This criteria would minimize the advantage of this technique over the patellar tendon technique concerning the initial anterior pain.

Purpose: We reviewed retrospectively 349 cases of infected total hip arthroplasty treated by prosthesis replacement. The surgical strategy, 127 single-stage procedures and 222 two-stage procedures, was determined by the surgeon on a case by case basis.

Material and methods: At least one positive sample during the clinical history was required for inclusion in the series. Results of all bacteriological samples collected pre- and intra-operatively were noted. Samples were considered reliable if obtained from a deep site (puncture, biopsy, intraoperative specimen) and non-reliable if obtained from any other site. We studied the agreement between preoperative and intraoperative samples, taking the intraoperative samples as the reference, in order to determine the effect of complete preoperative knowledge of the causal germ on the outcome of infection treatment at last follow-up.

Results: For single-stage replacement procedures, preoperative samples were reliable in 74 cases (58%) and non reliable in seven (6%); they were sterile or absent in 46 cases (36%). Intra-operative samples were positive in 103 cases (81%). Agreement between the preoperative and intraoperative samples was observed in 48 cases (38%). The rate of success was not different if the surgeon had or did not have reliable knowledge of the causal germ(s) preoperatively: successful treatment in 66 cases (89%) with knowledge and successful in 46 cases (87%) without knowledge. For two-stage procedures, preoperative samples were reliable in 155 cases (70%) and non-reliable in 15 (7%); they were sterile or absent in 52 cases (23%). Intraoperative samples were positive in 178 cases (80%). Agreement between preoperative and intraoperative samples was observed in 107 cases (48%). The rate of success was not different if the surgeon had or did not have reliable knowledge of the causal germ(s) preoperatively: successful treatment in 133 cases (86%) with knowledge and successful treatment in 56 cases (84%) without knowledge.

Conclusion: Reliable preoperative knowledge of the causal germ(s) did not affect the rate of success for single-stage or two-stage total hip arthroplasty replacement procedures. These findings do not corroborate the notion that it is absolutely necessary to recognise the germ(s) causing the infection before undertaking a single-stage replacement procedure.

Purpose: After implantation of a total knee arthroplasty (TKA) for osteoarthritis, early demineralisation of the superior tibial epiphysis occurs with modification of bone mineral density (BMD) in the two compartments. The long-term trend is not known to date. We report the results of 38 prostheses followed prospectively with densitometric measurements at minimum five years.

Material and methods: This prospective analysis included 38 TKA implanted for primary degenerative disease in patients with a mean age of 70±4 years at implantation, 60% women. Clinical assessment (IKS) and radiography (HKA) as well as osteodensitometry were recorded before surgery, at six months, one year, two years and five years. Bone mineral status was assessed using the densitometry of the femoral neck before surgery and at five years for all patients. The DEXA method was used for each knee on the anteroposterior film. Seven zones were defined around the tibial implant, in particular two under the medial and lateral plateaus, and under the stem. We studied changes in each zone over time. The alpha risk was set at 5%. Inter- and intraobserver reproducibility was 2.9% and 2.8% respectively.

Results: At five years follow-up, the mean IKS function score was 85±19 and the knee score was 918. The mean mechanical axis was 180±2° with symmetrical distribution. There were no progressive lucent lines. The BMD of the homolateral femoral neck did not change significantly (0.763 g/cm2 at inclusion and 0.750 g/cm2 at five years), unlike the natural evolution in a reference population (women -4.5%, men -2.4%). The mean BMD in the seven zones decreased significantly (11.6%, p< 0.0001. Mean BMD was 0.936 g/cm2 at inclusion and 0.863 g/cm2 at six months), 0.823 g/cm2 at five years. BMD decreased very strongly from 0 to 6 months (−6.51%, p< 0.0001) then more slowly to the end of the first year (−3%) and finally declining regularly, but non-significantly, at a slower rate from 1 to 5 years. Study of the seven zones showed a difference in changes in the BMD between the medial, lateral and stem zones. The two medial zones decreased significantly from 6.33% to 6.18% especially during the first year (−2.06% and −2.09%) and more moderately from 1 to 5 years (−1.6%, −2.65%). The lateral zones showed a greater average decline in BMD (−10.5%, −8.92%) between 0 and 5 years: −8.57% and −6.75% during the first year then at a slower rate. The greatest loss in BMD was found under the stem; −14.3% at five years. Here again, between 0 and 6 months the decline was rapid: −8.09%. It reached −12.74% at one year then varied little, −1% and −2% between 1 and 5 years.

Conclusion: 1) Bone remodelling under the tibial base plate occurs early after implantation of a TKA. It occurs during the first year (especially the first six months). 2) Remodelling is more pronounced laterally than medially (good realignment but persistent varus stress with greater stress on the medial than lateral side). 3) The greatest loss in BMD occurs under the stem. 4) BMD of the femoral neck remains stable, unlike the evolution observed in a reference population.

Purpose: The position of the femoral implant in external rotation remains a controversial issue. It can be determined using bone landmarks (Whiteside line, parallel to the biepicondylar axis, 3° external rotation from the posterior condylar plane). For the last seven years, we have related femoral rotation to the orientation of the tibial cut in order to ensure good femorotibial stability in flexion using specific instruments (Cores®). This prospective study was conducted to examine the position of the femoral implant determined with this method and to measure the position from bone landmarks.

Material and methods: Twenty consecutive patients were included in this study. Bilateral computed tomographic measurements were made before and after surgery. Joining 8mm/8 slices were obtained for the femoral necks and 5mm/3 slices for the knees. The angle of femoral torsion was defined in two ways: the first by the angle formed between the axis of the femoral neck (on two superimposed slices) and the tangent to the most posterior part of the femoral condyles; the second by the angle formed between the epidondylar line and the posterior condylar line.

Results: The preoperative scans demonstrated that the angle between the biepicondylar line and the posterior condylar line was 5.8±1.5°. Using Cores®, led to an external rotation of the femoral implant to 2.7±0.6°. The postoperative scans demonstrated that the angle between the biepicondylar line and the posterior condylar prosthetic play was a mean 3.3°. The measurements using the femoral neck were less precise, with, in one case, an external rotation of 5°. The patella was well balanced postoperatively (irrespective of the external rotation position of the femoral implant).

Discussion: The angle of about 6° between the biepicondylar line and the posterior plane of the condyles has also been reported by others (Beaufils, Matsuda). To obtain a rectangular space in flexion, the posterior condyle cuts are more important medially than laterally. We found a correlation between the correction provided by the specific instrument set and the difference in the posterior condyle cuts, demonstrating the intraoperative precision of Cores®. It is difficult to orient the femoral piece parallel to the biepicondylar axis. This study demonstrates that there always remains 2 to 3° of inclination of the biepi-condylar axis from the posterior condylar plane.

Conclusion: The positioning the femoral implant parallel to the biepicondylar line leads to inducing an important external rotation. While using 3° rotation systematically would reduce the risk of internal malrotation, we feel it better to adapt the rotation to each individual knee depending on the anatomic presentation. Cores® enables positioning the femoral implant in external rotation as a function of the ligament balance obtained in flexion after peripheral tension is applied. This enables avoiding medial femorotibial laxity in flexion.

Purpose: Free patellar tendon plasty is classically used for the treatment of chronic anterior instability of the knee. Good functional results may however be compromised by invalidating anterior pain. The purpose of this randomised trial was to obtain a prospective comparison of outcome after hamstring plasty or patellar tendon plasty.

Material and methods: One hundred patients with an isolated tear of the anterior cruciate ligament were included in the study between May 1998 and 2001. Exclusion criteria were history of fracture, grade II laxity, and tear of the contralateral ACL. Patients were assigned to one of the treatment arms in random order in the operating room: Group A: arthroscopic free patellar tendon-bone graft; Group B: arthroscopic free four-strand hamstring graft. Two metal interference screws were used for fixation in all cases. The Aglietti method was used to calculate the position of the bore holes in all cases. The same rehabilitation protocol, in the same centre, was applied in all cases. The two groups were comparable for epidemiological, clinical, radiological, and instrumental laxity (KT1000®) data. IKDC criteria, activity level (sports), and instrumental measurement of laxity (KT1000® Medtronic) were used to assess outcome. Differences were considered significant for p < 0.05.

Results: At mean follow-up (24 months, range 6 – 38) groups A and B were not significantly different for delay to resumed sports activity at the initial level, motion, clinical examination of ligaments, IKDC global score, and radiological evolution. At six months, 30% of the patients in group A complained of anterior pain; 20% of the patients still complained of pain at one year. In group B, femoropatellar pain or pain at the harvesting site was reported by 8% of the patients at six months and 4% at one year (p = 0.0005). These differences were no longer present at two years. The instrumental differential laxity was 0.66±1.1 mm in group A and 1±1.5 mm in group B (p =0.20). Two repeated trauma-induced tears were observed in group B.

Conclusion: The preliminary results of this prospective randomised trial confirm the low morbidity of the harvesting site for hamstring grafts and the reliable stability of hamstring repair of isolated ACL laxity. A longer follow-up is however needed for long-term validation, particular concerning secondary distension of hamstring grafts as is frequently reported in the literature and which we have also observed in certain patients treated before this series.

Purpose of the study: This prospective study was conducted to analyze the mechanisms of gait compensation in patients with painful hip and to search for correlations with preoperative clinical and radiographic findings.

Material and methods: Optoelectronic and multicomponent force-plate datas were used to calculate joint motion, moments and intersegmental forces for 26 patients with unilateral hip pain and 20 normal age and sex-matched patients. Height was similar in the two groups but mean weight in the study group (83 kg) was greater than in the controls (68 kg). The preoperative Harris score was 53 in the study group and 16 patients had a permanent flexion contracture of the knee (mean 15°, range 5–30°). Radiographically, there were 22 cases of osteoarthritis hip disease and 4 cases of necrosis.

Results: Gait analysis showed a significant 0.66 ± 0.06 m (12 p. 100) reduction in step length. Patients who had severe hip pain walked with a decreased dynamic range of motion (18 ± 5°, p < 0.0001) with a curve reversal as they extended the hip. They also reduced dynamic range of motion of the knee and ankle. Patients who presented a reversal in their dynamic hip range of motion had a greater passive flexion contracture and a greater loss in range of motion during gait than those with a smooth regular pattern (p < 0.0001). Patients with hip pain walked with significantly decreased external extension, adduction, and internal and external rotation moments (p < 0.0001). They also unloaded the ipsilateral knee and ankle. The decreased hip extension moment was significantly correlated with an increased level of pain (p < 0.0001). There was no correlation with radiological findings.

Discussion: Reversal of dynamic hip range of motion was interpreted as a mechanism to increase effective hip extension during stance phase through increased anterior pelvic tilt and lumbar lordosis.

Conclusion: Patients with painful hip walked with a manner that was asymmetric. These gait modifications were related to hip limitation in passive motion and pain. Patients with flexion contracture adopted a compensatory gait mechanism. This study confirms relation between hip pain and forces across the hip joint.

Purpose: Arthroscopic reconstruction of the anterior cruciate ligament (ACL) with a free patellar tendon graft is a classical method for the treatment of anterior knee laxity. The purpose of this study was to analyse clinical and radiological outcome in 218 cases at five years and to search for prognostic factors.

Material and methods: Between 1993 and 1994, arthroscopic repair of the ACL was performed in 218 knees with two independent tunnels using a free patellar graft. This prospective study included 177 knees reviewed at a mean 67±7 months follow-up using the IKDC criteria and instrumental manual KT-1000 laxity measurements. The series included 67.4% men and 32.6% women, mean age 26.7 years (14–59). Delay from the accident to surgery was a mean 22.3 months (1–228 months). Two medial, 15 lateral and five medial and lateral meniscectomies had been performed before the operation studied. The position of the tunnels was studied using the Aglietti method. Differences were considered significant at p < 0.05.

Results: Sports activities could be resumed in 87% of the cases at the same level for 62% with a mean delay of 12 months. Subjectively, the patients were satisfied or very satisfied in 86% of the cases. Symptom score was A in 50%, B in 38%, C in 8.3% and D in 3.7%. Maximal manual residual differential measured with KT-100 was 0.75 ± 2.3 mm with an abolished click in 82% of the cases and a glide in 12%. Sceondary medial meniscectomy was performed in 19 cases. At last follow-up the meniscal material was intact in 127 cases (60%). Overall IKDC score for the 177 cases reviewed was: A 57%, B 24%, C 9%, D 9%. Radiographically, the knee was normal in 66.6% of the cases, remodelled in 29.6%, and exhibited joint space narrowing less than 50% in 13.4% and overall osteoarthritis in 0.6%. The Aglietti lateral score as 25.5±7% for the tibia and 66.3±7.2% for the femur. During follow-up, there were 13 cases of recurrent tears related to repeated sports trauma or poor femoral position. During this same period, there were 20 tears of the contralateral ACL. Functional outcome was correlated with the presence of a medial meniscus, the length of delay from accident to surgery, and the presence of radiological evidence of residual laxity.

Conclusion: This study demonstrated that chronic anterior laxity of the knee, treated with a free patellar tendon graft implanted arthroscopically provides good restoration of the knee in 82% of the cases with little residual laxity. Joint space narrowing was found in 1% of the cases and was strongly correlated with the status of the medial meniscus that should be preserved. The number of recurrent tears was equivalent to the number of contralateral tears observed during the same period.

Purpose: Tibiotalar arthrodesis is a classical procedure for the treatment of painful deformation-destruction of the tibiotalar joint. The purpose of this retrospective study was to determine prognostic factors and tolerance to tibiotalar arthrodesis observed in 68 procedures performed with two different techniques (47 surgical fusions (Group 1), and 21 arthroscopic fusions (Group 2)).

Material and methods: Between 1985 and 1999, 68 patients, mean age 51 years (22–88) underwent 55 arthrodesis procedures (47 post-traumatic, 2 paralytic, 6 rheumatoid polyarthritis, 4 sequelae of septic arthritis). All patients had major functional impairment. The tibiotalar joint was stiff in all cases and mean motion was 20 ± 15°. The subtalar facet was nearly normal in 33 cases, altered in six and had already fused in nine. The mediotarsal facet was altered in 12 cases, six had already had a double arthrodesis, and was normal in 50. On the preoperative Méary view, there was a normal axis in 13 patients, valgus in 28 and varus in 24. According to the Duquennoy radiographic criteria, there was subtalar involvement in 32 cases and mediotarsal involvement in 19. Tibiotalar arthrodeses procedures were performed arthroscopically after 1993 for cases with little axial deformation. Open surgery was used for all other cases (43 Méary technique). A plaster cast was used in all cases. All patients were reviewed using the Duguennoy score and two radiographic views: lateral weight-bearing view for the sagittal plane position (tibiopedious angle) and the Méary view for the frontal plane.

Results: At a mean follow-up of four years, fusion rate was 82% (group 1 83%, group 2 81%). Mean delay to fusion was 3.2 ± 1 month irrespective of the causal disease or surgical technique. Functional outcome was very good in 28%, good in 34.5%, fair in 34.5% and poor in 3% and did not depend on the surgical technique. The subtalar was painful with zero motion in 18 cases (26.5%), generally associated with residual equine. The mediotarsal was stiff in 17 cases and very painful in four. In the frontal plane, 16 ankles were correctly axed, 27 were in valgus (mean 5.6°) and 20 in varus (mean 7.6°) with no difference between the two groups. In the sagittal plane, four ankles were in talus, nine in neutral position, and 49 had a residual equine, including 32 > 5°. In most cases, fair or poor outcome was related to subtalar pain. More than 50% of the patients with equine fusion greater than 5° had subtalar pain.

Conclusion: For the same deformity, arthroscopic arthrodesis can shorten hospital stay and improve the rate and degree of trophic disorders. Arthroscopic tibiotalar arthrodesis is an elegant technique that we use for centred ankles or for patients with risk factors, particularly skin conditions. The rate of fusion with the arthroscopic approach is not however better than with open surgery. Precise clinical and radiological assessment of the subtalar facet as well as the position of the fusion in the sagittal plane at 90° without equine deviation are important prognostic factors observed in this series.

Purpose: After cementing, various changes are observed in femoral bone resulting from various factors (ageing process, stress forces, granuloma…). The purpose of this work was to examine the radiological expression of these changes a mean 12 years after prosthesis implantation.

Material and methods: Charnley-Kerboull total hip arthroplasty was performed in 304 patients (338 hips) between January 1st, 1984 and December 31st, 1986. Mean age of the population was 65.5 years. Most of the patients had degenerative hip disease (81.4%). Among these 304 patients, 108 had died and 56 were lost to follow-up, giving 174 patients retained for analysis at a maximum follow-up of 16 years (mean 12 years). Noble and Nordin scores were recorded before surgery and during follow-up as were the cortical and cement thicknesses in the seven zones described by Gruen.

Results: The actuarial curve, calculated for the 338 hips showed 95.1% survival at 12 years (taking into account all revisions irrespective of the cause). Femoral stem survival was 97.1±2% taking certain or probable loosening as the endpoint. Several categories or radiological changes were observed: – femoral defects (18%) correlated with cup wear; – progressive widening of the medullary canal without loosening and a mean femoral score moving from 55.7 to 52.16 (p< 0.01) especially in thin women and for wide-mouthed femurs; – cortical thickening near the tip (57%) more frequently for greater distal filling; – stress shielding especially in women (p< 0.001) with a low initial score for the femur (p< 0.0006) and with greater distal filling.

Conclusion: Like Kerboull, we tried to achieve primary stem stability before cementing. Cementing results were good (97% at 12 years), but detailed radiographic analysis demonstrated that cortical thinning remained in zone 7, especially when the primary stability was achieved in the distal portion of the femur (high preoperative Noble index). Variations in the metaphyseal-diaphyseal ratio require adaptating the form of the stem to be cemented in order to achieve better filling and avoid primary stability mainly in the distal portion.

Purpose: The MacIntosch method for reconstruction of the anterior cruciate ligament using a free intra-articular plasty with an extra-articular reinforcement was the classical treatment during the eighties for chronic anterior laxity. In 1992, we reported our short-term resuls in 180 cases. The purpose of this report is to analyse the results in 112 of these 180 cases with a mean follow-up of 14 years.

Material and methods: One hundred twelve knees operated between 1982 and 1987 were included in this study. There were 82 men (73.2%) and 30 women (26.8%), mean age 24.9±5.8 years. Mean follow-up was 165.3 ± 25.9 months. Mean delay from accident to repair was 30.9 months (3–144) and meniscectomy was performed in 88% of the cases, mainly for contact pivot sports (85%). All patients had an overt laxity (advanced in 73.2% or isolated in 26.9%). The MacIntosh plasty performed by arthrotomy used a patellar tendon with a quadriceps tendon band prolongation. Arthros-copy was performed prior to surgery in all cases. If the transplant was implanted over the top, the radiographic analysis of the tunnel position was only made for the tibia. An independent examiner reviewed all the patients clinically and radiographically using the IKDC criteria with instrumental KT 1000 measurements.

Results: Sports activities were resumed in 78% of the cases with a trend towards pivot sports without contact practised in an amateur setting. Subjectively, 69.6% of the patients were very satisfied and 25% were satisfied. The click was abolished in 83% of the cases, was minimal in 15% and overt in 2%. The medial meniscus was intact in 40% of the cases with only 10 secondary meniscal tears 14 years later. The residual manual maximal traction differential at KT 1000 was 1 ± 1.225 mm and the mean compliance was 1.69 ± 1 mm. The overall IKDC score was: 31% A, 47/6% B, 19.1% C, 1.9% D. X-rays were normal in 17%, showed remodelling in 55.4%, and joint narrowing < 50% in 23.8% and > 50% in 3.8%. For patients with an intact medial meniscus, joint narrowing was observed in 5.5% compared with 24% after resection of the medial meniscus. There were two repeat tears in this series compared with 22 tears of the contra-lateral anterior cruciate ligament. The unsatisfactory results (22%) were related to anatomic failure (two cases) and functional problems (18 cases, defective mobility and pain). The prognostic factors were age at time of operation and preservation of the medial meniscus.

Conclusions: This study confirms the persistently good clinical and functional results 14 years after plasty using the patellar tendon associated with lateral reinforcement. Ligament stabilisation was satisfactory but it must be recalled that at 14 years, the functional needs were different for these knees. The radiological course was more worrisome with joint narrowing in 27.6% of the cases.

Four en-bloc resections for malignant tumours of the hip, the peri-acetabular region and the iliac wing were reconstructed using an irradiated hemipelvic allograft together with a total hip prosthesis. Technical aspects include the use of an anterior Enneking approach which excises the previous biopsy site, division and re-attachment of the iliac crest and fixation of the prosthesis using a modified acetabular cup and three polypropylene artificial ligaments to increase the stability of the joint. Weight-bearing was allowed at three months. The oncological and clinical results were satisfactory after a mean follow-up of 19 months, with walking distances of 500 metres to two kilometres without pain.