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Las laxitudes perifericas cronicas de la rodilla pueden producirse de forma aislada, pero suelen asociarse a una lesion del pivote central. No suelen recibir tratamiento, porque en la mayoria de las ocasiones no se diagnostican. Sin embargo, la anatomia y la biomecanica de las estructuras son bien conocidas gracias a varios trabajos recientes, aunque es indispensable realizar un analisis clinico preciso para caracterizar estas laxitudes. Las radiografias dinamicas y la resonancia magnetica (RM) completan la exploracion. Si no se realiza un tratamiento quirurgico, el resultado funcional se ve seriamente comprometido. En este articulo se describen el papel, la biomecanica y las tecnicas (clasicas y recientes) de las plastias anterolaterales. Se estudiaran los dos compartimentos de la rodilla (medial y lateral): anatomia, biomecanica y pruebas clinicas. Este analisis permite distinguir las laxitudes aisladas de las laxitudes combinadas. Se exponen las tecnicas quirurgicas para cada compartimento: vias de acceso y localizaciones radiologicas de las inserciones ligamentarias. En cada tipo de laxitud, despues de recordar las tecnicas clasicas se describen las tecnicas mas recientes, junto con sus argumentos anatomicos y biomecanicos, detallando los fundamentos de la rehabilitacion. Por ultimo, se establecera el orden de reconstruccion de las plastias perifericas laterales y de los elementos del pivote central, asi como el papel de la osteotomia direccional de valguizacion, basandose en los aspectos biomecanicos.

Riassunto Le lassita periferiche croniche del ginocchio possono essere isolate, anche se di frequente sono associate a una lesione del pivot centrale. Sono trascurate perche spesso la loro esistenza e ignorata. L’anatomia e la biomeccanica delle strutture sono tuttavia ben note grazie a studi recenti, ma e indispensabile un’analisi clinica precisa per caratterizzare tali lassita. Le radiografie dinamiche e la RMN completano l’esame. In assenza di trattamento chirurgico, il risultato funzionale e seriamente compromesso. Sono definite la sede, la biomeccanica, le tecniche (storiche e recenti) delle plastiche anterolaterali. Sono studiati i due compartimenti del ginocchio (mediale e laterale): anatomia, biomeccanica e test clinici. Questa analisi permette di distinguere le lassita isolate dalle lassita combinate. Vengono presentate le tecniche chirurgiche per ciascun compartimento: vie d’accesso e localizzazioni delle inserzioni legamentose. Per ciascun tipo di lassita, dopo un cenno sulle tecniche storiche, vengono presentate le tecniche piu recenti insieme alle loro motivazioni anatomiche e biomeccaniche. Si espongono sinteticamente i principi di riabilitazione e viene stabilito in base alla biomeccanica l’ordine di ricostruzione delle plastiche periferiche laterali e degli elementi del pivot centrale, cosi come il ruolo dell’osteotomia di valgizzazione.

Summary Introduction Accurate positioning of the acetabular cup in primary total hip arthroplasty is critical to decrease the rate of dislocation. Inaccurate orientation of the cup is the most common error during this procedure. Target acetabular orientation is still controversial. An original study found a dislocation rate of 0.6% when the cup was aligned with the transverse acetabular ligament (TAL). Hypothesis TAL is a patient-specific anatomical landmark and a tool for cup orientation. Materials and methods Eight cadaveric pelves (14 hips included for study) were harvested in toto at our research laboratory. Anatomical versions of the TAL, labrum and horns were measured in relation to the anterior pelvic plane. A navigator sensor and an optoelectronic device (Motion Analysis™) were used. Results Anatomical versions of the TAL, horns and labrum averaged 1.9° (range, −8° to +13.3°), 3° (range, −12.2° to 14°), and 26.3° (range, 17.4° to 41.8°), respectively. Discussion To our knowledge, this is the first study to report the orientation of the periacetabular soft-tissues. TAL anteversion was outside the safe zone described by Lewinnek, while labrum anteversion was within this safe-zone. We discuss the reference used, Lewinnek's safe zone, and functional orientation of the implants. Lewinnek's safe-zone does not seem to be valid. The TAL seems to be a specific reference for each patient but its reliability must still be confirmed as an adequate reference for positioning the cup in total hip arthroplasty. Level of evidence Level IV Prospective study.

Model-image registration techniques have been used extensively for the measurement of joint kinematics in vivo. These techniques typically utilize an explicit measurement of X-ray projection parameters (principal distance, principal point), which is easily done for prospective studies. However, there is vast opportunity to derive useful information from previously collected clinical radiographic films where the projection parameters are unknown. The purpose of this study was to determine variation in measured knee arthroplasty kinematics when the X-ray projection parameters were unknown, but bounded. Based on the clinical radiographic protocol, a nominal principal point was chosen and eight additional points +/-2 and +/-5 cm in the horizontal and vertical directions were defined. Tibiofemoral kinematics were determined for all nine projection parameter sets for a series of 10 lateral radiographs. In addition, the principal distance was varied +/-15 cm and tibiofemoral kinematics were determined for these two projection sets. Measured joint kinematics varied less than 0.6 degrees and 0.4 mm for +/-2 cm variations in principal point location, and 0.7 degrees and 0.6 mm for +/-5 cm variations in principal point location. Measured joint kinematics varied less than 0.6 degrees and 0.7 mm for +/-15 cm variations in principal distance. Variation in X-ray principal point and principal distance over clinically bounded ranges has a small effect on knee arthroplasty kinematics computed from model-image registration with high-quality clinical radiographs.

Resume L’osteochondrite des condyles femoraux est une lesion rare. Cette etude multicentrique analyse 892 cas issus d’une serie pediatrique et adulte. Les lesions anatomiques sont plus evoluees chez l’adulte. L’analyse globale montre que la majorite des enfants a un tres bon resultat clinique, mais il y a une forte proportion d’enfants dont les radiographies ne sont pas encore normales. Pour les adultes, il y a une forte proportion de patients qui vont bien cliniquement alors que leur radio n’est pas normale. L’interpretation de la radio standard est delicate. Nous avons defini 3 classes radiographiques, lacunaire, nodulaire et niche vide. L’IRM permet une analyse plus precise de l’interface os-fragment, du cartilage surfacique, du potentiel de croissance et de la vitalite du fragment. L’arret des sports est le traitement de premiere intention chez l’enfant. Les perforations transchondrales sont une intervention simple de faible morbidite, amenant la guerison dans 48% des cas en 6 mois, si le cartilage de croissance est ouvert. La fixation du fragment a ete faite dans 43% des cas avec un clapet cartilagineux. Cette intervention donne des resultats moyens qui se degradent en fonction de la stabilite du fragment. L’operation de Wagner donne des resultats inferieurs aux perforations. L’ablation du sequestre est une operation peu invasive, mais son devenir a long terme est arthrogene, surtout chez l’adulte. Les greffes en mosaique donnent a moyen terme de bons resultats. Il y a peu de morbidite surtout si les greffes sont prises au dessus de l’echancrure. La greffe de chondrocytes, est de mise en œuvre difficile. Les resultats a moyen terme sont bons pour de larges lesions. L’osteotomie est logique en cas d’arthrose debutante. Les points a retenir 1) Le pronostic est meilleur avant la fermeture de la plaque de croissance. 2) L’osteochondrite necessite une exploration complementaire anatomique et fonctionnelle par l’IRM. 3) Il ne faut pas laisser passer le moment de la perforation transchondrale chez l’enfant. 4) Le vissage seul n’est pas toujours suffisant. Il faut ameliorer la trophicite, la revascularisation du fragment. 5) Les greffes mosaiques sont preferables a l’ablation du fragment. 6) Les greffes de chondrocytes seront plus utilisees pour demain.

La osteocondritis disecante de los condilos femorales es una afeccion poco comun cuya causa exacta se desconoce. Sin duda alguna responde a muchos factores; entre ellos, los factores mecanicos y vasculares se encuentran en primer plano. Es una afeccion artrogena cuando aun no se ha logrado la cicatrizacion. Existe una forma juvenil, con capacidad de cicatrizacion, y una forma del adulto que a menudo requiere cirugia. El objetivo de la cirugia es alcanzar la cicatrizacion de la lesion osteocondral gracias a un injerto oseo y a una osteosintesis. Cuando el fragmento esta despegado, o es imposible fijarlo, se puede optar entre dejar el defecto osteocartilaginoso tal como se encuentra o tratar de rellenarlo. Las tecnicas posibles son numerosas: injertos en mosaico, injertos de condrocitos o aloinjertos, que aun no han dado pruebas respecto a su longevidad.

Osteoarthritis is the most prevalent chronic joint disorder. Traditional surgical procedures that address the arthritic knee involve bone re-alignment such as high tibial osteotomy or resurfacing by total knee arthroplasty and unicompartmental arthroplasty. Arthroscopic treatment could be an option in the management of osteoarthritis of the knee. Arthroscopic management of the osteoarthritic knee has become popular; this is due at least in part to the fact that the more complex surgical alternatives require longer recovery periods, are more costly, and are associated with greater morbidity. Although the primary goal of arthroscopic surgery is to provide pain relief, one of the benefits of this minimally invasive approach is that it enables patients to continue their regular activities and to delay.

The aim of this study was to test (a) three methods to estimate the quantity of lactate accumulated (QLaA ) in response to supramaximal exercise and (b) correlations between QLaA and the nonoxidative energy supply assessed by the accumulated oxygen deficit (AOD). Nine rowers performed a 3-min all-out test on a rowing ergometer to estimate AOD and lactate accumulation in response to exercise. Peak blood lactate concentration [(La)peak ] during recovery was assessed, allowing QLaA(m1) to be estimated by the method of Margaria et al. Application of a bicompartmental model of lactate distribution space to the blood lactate recovery curves allowed estimation of (a) the net amount of lactate released during recovery from the active muscles (NALR max ), and (b) QLaA according to two methods (QLaA(m2) and QLaA(m3)). (La)peak did not correlate with AOD. QLaA(m1), QLaA(m2) and QLaA(m3) correlated with AOD (r = 0.70, r = 0.85 and r = 0.92, respectively). These results confirm that (La)peak does not provide reliable information on nonoxidative energy supply during supramaximal exercise. The correlations between AOD and QLaA(m2) and QLaA(m3) support the concept of studying blood lactate recovery curves to estimate lactate accumulation and thus the contribution of nonoxidative pathway to energy supply during supramaximal exercise.

Base alumina ceramics with dispersoids (BAC) are a new class of ceramics with improved mechanical properties as compared to pure alumina. They are obtained by dispersion of powder within an alumina matrix. Of the three new ceramics studied here, A20Z possesses the best mechanical properties as well as tribological properties superior to those of pure alumina whether it is used in ceramic-ceramic or ceramic-polyethylene combination.

Total knee replacement (TKR) for treatment of osteoarthritis in a valgus knee is, in most cases, not more challenging than in a varus knee. However, in the presence of severe valgus deformity, it is more difficult to achieve good ligament balance and adequate bone coverage, despite contracture of the lateral structures. The worst case scenario is a mixed deformity which combines wear, contracture of lateral structures, slackening of medial ligamentous structures, and extra-articular bone deformity as may be seen after tibial osteotomy or post-traumatic malunion.

We report two cases of ochronosis. This rare disease (1/1,000,000) transmitted by recessive autosomic inheritance results from an enzyme disorder. Clinically, the disease begins by black deposits in connective tissue followed by a group of symptoms, particularly involving the joints, and then destructive joint disease affecting the larger joints. Diagnosis is often established late. Early detection is important, preoperatively if possible, in order to avoid the serious complication of infectious endocarditis. These patients require adapted multidisciplinary care associating social support and symptomatic treatment. Drug therapy is currently under study and appears to provide effective symptom relief.

We studied the incidence and the impact of patellar fracture after anterior cruciate ligament (ACL) reconstruction, comparing two harvesting techniques.Series A included Kenneth Jones ligamentoplasties (n=1234). The distal and central part of the patella were harvested using an oscillating saw and a gouge. Series B included 676 Mac InJones reconstructions performed during the same period. The patellar cut was done from porximal to distal its attachment were harvested with a manual wire saw. The bony harvesting site was filled with cancellous bone.There were three postoperative transversal patellar fractures (0.24%), all in series A. Functional outcome was disappointing but there was no impact on knee stability.The fact that the Mac InJones technique does not involve a transversal cut would apparently prevent secondary fracture.

This was a retrospective series of patients who underwent revision ligamentoplasty of the anterior cruciate ligament (ACL). We wanted to assess the functional outcome after this type of surgery and search for potential prognostic factors.The series included 74 patients, mean age 34 years (range 21-59 years). The initial ligamentoplasty was performed with a synthetic ligament (n=16), an autograft (n=57) or an allograft (n=1). Differential laxity (KT-1000 maximal manual) was 7 +/- 2.5 mm. Anterior drawer was measured on the stress x-rays in 20 degrees flexion: medial 8 +/- 4.7 mm, lateral 8.3 +/- 4.9 mm. Mean time to revision surgery was 78 months. Reconstruction was performed arthroscopically in 69 knees. The implant used for the revision reconstruction was an autograft: patellar tendon (n=42), quadriceps tendon (n=15), hamstring tendon (n=13), patellar tendon and quadriceps tendon (MacInJones) (n=3), fascia lata (n=1). A meniscal tear was noted in 24 knees and a cartilage lesion in 35.Outcome was assessed at mean 21.2 months follow-up. The mean IKDC function score was 71.7 (range 21.8-100). 78% of patients considered their knee normal or nearly normal and 88% presented a positive Lachmann. Mean differential laxity measured with KT-1000 (maximal manual) was 2 +/- 1.7 mm. Stress x-rays revealed a mean differential laxity measured at 3.7 +/- 2.3 mm medially and 6.3 +/- 4.3 mm laterally. The presence of a meniscal lesion favored osteoarthritic degradation. Presence of chondral lesions altered the functional outcome significantly and limited resumption of sports activities. An initial repair using a synthetic ligament affected the functional outcome after revision surgery and favored or aggravated chondral lesions.The clinical results we have obtained with revision ACL ligamentoplasty are comparable to previous series reported in the literature. The functional outcome is not as good as after first-intention repair, especially if the initial plasty was done with a synthetic ligament and the knee presented meniscal or cartilage damage.

La majorite des gonarthroses sur genu valgum ne pose pas des problemes techniques plus difficiles que les genu varum et les resultats sont comparables.

The aim of this retrospective analysis was to report results obtained with a self-centering patellofemoral prosthesis. We wanted to determine whether self-centering still has indications for the treatment of patellofemoral osteoarthritis.This was a continuous series of 57 knees operated on since 1986 in the same center for implantation of a self-centering patellofemoral prosthesis (Medinov then Depuy). Eight patients died and four were lost to follow-up. Two knees were excluded from the analysis after revision with a PFP. We report here the outcome of 43 prostheses at mean follow-up of six years two months (range 78 months to 15 years). The IKS score (200 points) and the ADL scale (in %) were recorded. The position of the prosthesis was assessed on plain X-rays. Mean age at implantation was 67.2 years. The main reasons for surgery were osteoarthritis secondary to dysplasia (60%) and primary disease (31.1%).At last follow-up, the IKS score was 157.2 points (range 76-195). The mean ADL score was 74.1/100 (48.8-96.3). The IKS evaluation showed good outcome in 66.7% of knees. The ADL scale gave a less satisfactory outcome: 57.7% good outcome for this scale which takes into account all knee functions for activities of daily life. Outcome was better among patients with trochlear dysplasia. Eleven patients (24.4%) had had revision surgery for total knee arthroplasty. Preoperatively, the trochlear angle was smaller in revision cases (p=0.023). In these patients, the first prosthesis was more anterior (p=0.004) with a greater horizontal axis (p=0.015).Our outcomes were less satisfactory than the average results in the literature. It must be noted however, that the concept of a good outcome depends on the scale used for assessment. We found in our series a 10% difference between the ADL scale and the IKS score. Independently of the assessment scale used, outcome was better in knees with osteoarthritis secondary to dysplasia. An analysis of the X-ray findings disclosed technical errors leading to failure. The outcome of patellofemoral prosthesis depends essentially on two factors: technical precision and patient selection.In light of these findings, we have come to limit still further the rare indications for patellofemoral prostheses. The typical indication is isolated advanced patellofemoral osteoarthritis secondary to patellofemoral dysplasia unresponsive to medical treatment in patients aged 50-70 years. Revision with a total knee arthroplasty required changing the patellar insert if worn. We have not had any particular problem with revision total knee arthroplasty after patellofemoral prosthesis.

Reconstruction of the anterior cruciate ligament (ACL) is a common procedure, but use of lateral reinforcement is still a subject of debate. The purpose of this study was to compare two randomized series of ACL reconstructions, one using an intra-articular method (patellar tendon autograft) and the other an intra- and extra-articular method (Mac-InJones).From January 1995 to March 1998, 63 knees underwent surgery for ACL reconstruction. Inclusion criteria was significant medial differential laxity measured between 7 and 12 mm on passive dynamic x-rays as 20 degrees flexion. Group 1 (patellar tendon intra-articular reconstruction) included 34 patients (27.1+/-7.5 years) and group 2 (intra-articular reconstruction plus extra-articular quadircipital tendon plasty) included 29 patients (28.5+/-12 years). The IKDC score was determined for 72% of the knees in group 1 and 68% in group 2 at seven years follow-up on average (102 and 93 months respectively). Anterior laxity was measured radiographically and with KT-1000. The position of the tunnels was controlled using the Aglietti method.The subjective functional score was 83.6+/-3.5 in group 1 and 83.5+/-3.5 in group 2. The overall IKDC knee score classes for group 1 were 0% A, 52.4% B, 28.6% C, and 19% D and for group 2 were 5.5% group A, 50% group B, 33.3% group C, and 11.1% group D. In group 1, the pivot test was negative in 61.9% and noted stage 1 in 28.6% and stage 2 in 9.5%. In group 2, the pivot test was negative in 78.9% and noted stage 1 in 15.8% and stage 2 in 5.3%. The KT-1000 showed no difference in gain in laxity: 31% for group 1 and 27% for group 2. Similarly, radiographically there was no difference with a 43.9% gain in differential laxity for the medial compartment and 45.3% for the lateral compartment in group 1. In group 2 the corresponding values were 51.9% and 41.8%. The position of the tunnels was the same in the two groups.In a preliminary study with two years follow-up, the results in these two series were not significantly different. It was concluded that there was not clear advantage to adding the extra-articular lateral plasty. At the present 7-year follow-up, pivoting appears to be better controlled in the lateral plasty group (p=0.23), but with no significant difference for laxity for both knee compartments. The inclusion criteria would be different today and would be based on the laxity of the lateral compartment.

We conducted a retrospective radiographic study to identify and quantify medial and lateral misalignments in candidates for total knee arthroplasty.We studied a discontinuous series of 101 patients (164 knees) among candidates for total knee arthroplasty seen between 1990 and 2002. We selected a random sample for study. Exclusion criteria were any history of fracture, surgical treatment, rheumatoid disease, or congenital disorder. A first group of 136 genu varum knees was identified in 82 patients (mean age 72 years, mean weight 79 kg). A second group of 28 genu valgum knees was identified in 19 patients (mean age 67 years, mean weight 71 kg). The standard radiograms were digitalized for semi-automatic measurements using the Metros software. We recorded overall deformation, femoral valgus, tibial varus, HKA angle, HKS angle (mechanical/anatomic axis of the femur) and angle C (horizontal inclination of the ankle to the ground). All measures were compared between each other for each patient to search for relations.In the genu varum group (136 knees), mean overall deformation was 9 degrees , mainly due to tibial misalignment (5.5 degrees ) with a 1 degrees femoral valgus component. The HKS angle was 6.3 degrees , and lateral joint gap 4.3 degrees ; the C angle was 4 degrees . Overall varus followed tibial varus (p0.01). Ankle inclination followed tibial varus (p0.01). In the genu valgum group (28 knees), overall deformation was 4.2 degrees , mainly due to femoral misalignment (5.6 degrees) with 1 degrees tibial varus and a medial joint gap of 2 degrees . The HKS angle was 4.7 degrees and the mean C angle -4 degrees . Overall valgus was related to femoral valgus (p0.001). Tibial varus was greater with greater femoral valgus (p0.01). In both groups, the HKS angle was smaller with greater femoral valgus.Semi-automatic measurements on digitalized films enabled excellent reproducibility. Causes of error were related to limb rotation at acquisition. This study showed that genu varum worsens because of tibial wear followed by ligament distension, while for genu valgum, worsening predominantly results from femoral wear. The ankle joint line was nearly horizontal in one-third of the limbs, even when there was a major misalignment of the lower limb. The HKS angle was quite variable in both morphotypes, but was smaller with greater femoral valgus in both groups.Measuring all components involved in medial and lateral knee misalignment is very useful for understanding the morphotype of each individual knee before performing osteotomy or implanting a knee prosthesis.

The purpose of this retrospective study of a continuous series was to document preferential types and localizations of meniscal lesions accompanying anterior cruciate ligament tears and to demonstrate the relationships between meniscal lesions, patient age and time from trauma to surgery.One hundred fifty-six patients with no history of meniscal lesions underwent ligamentoplasty in 2003. All procedures were performed by the same operator. The time from trauma to surgery was 31.6 months on average. This was a retrospective continuous series using data from detailed operative reports.An isolated lesion of the medial meniscus was observed in 25.6% of cases. There was an isolated lesion of the lateral meniscus in 21.8% and lesions of both menisci in 9%. The most frequent injury was a longitudinal fissuration, for both menisci. Patient age and time from trauma to surgery were statistically correlated with presence of a medial lesion. There was no statistical relationship for the lateral meniscus nor for type of meniscal injury.The proportion of lesions to the lateral meniscus appeared to be unaffected by age or time to surgery after trauma, suggesting that lateral meniscal lesions occurred at the time of the initial curciate injury. On the contrary, the incidence of medial lesions increased with time and patient age, confirming the important role of the medial meniscus to block anterior displacement of the knee. We thus recommend early repair of anterior cruciate ligament tears in order to avoid medial meniscectomy which would increase with increasing time from injury to surgery and thus affect the postoperative outcome.

Short-term functional results and long-term outcome in terms of stability and wear greatly depend on the precision of the bone cuts. We wanted to know whether conventional ancillaries are still competitive in terms of accuracy in comparison with computer-assisted navigation systems. A few comparative studies favor navigation, but have generally only included a small number of patients. We studied radiographically a prospective consecutive series of 300 total knee prostheses (Innex, Zimmer) implanted with the conventional technique by the same operator.A telegonometric view in the upright position and a short lateral view were obtained in all patients. In the AP view, implants were measured in comparison with the mechanical axis of the femur (F) and the tibia (T). On the lateral view, the prosthesis-tibial shaft angle (PT) was measured from the proximal portion of the tibial shaft and the prosthesis-femoral shaft angle (PF) from the distal portion of the femur. The same operator made all measurements using the same optimal conditions. The series included 178 women and 122 men, mean age 72 +/- 8 years who presented genu varum (n = 248 knees) and genu valgum (n = 52 knees): degenerative disease (n = 238), polyarthritis (n = 4), hemophilic arthropathy (n = 3), necrosis (n = 3), revision of unicompartmental prosthesis (n = 8), and osteotomy (n = 44).The standard x-ray protocol was performed at two months in all patients. The mechanical axis (HKA) was 179.4 +/- 2.4 degrees (range 173-186 degrees) and was +/- 3 degrees in 87% of knees with no difference for varum and valgum. F was 90.1 +/- 1.4 degrees (87-95), with +/- 3 degrees for 98.7%. T was 89.3 +/- 1.5 degrees (85-94) with +/- 3 degrees for 95.6%. PF was 88.6 +/- 1.6 degrees (84-93) for 87%, PT was 87 +/- 2 degrees (81-93) with +/- 3 degrees for 94%. The four cuts were within +/- 3 degrees for 227 prostheses (77%), within +/- 2 degrees for 156 (52%) and within +/- 1 degrees for 56 (18%). Measurements made again one year after implantation for 203 knees gave the same results. Operative time for implantation was 68 +/- 23 minutes for implantation and 85 +/- 23 minutes including complete closure (less than 60 minutes for 68 knees).The accuracy of each cut was satisfactory on average with a small standard deviation. Recent data in the literature show that the accuracy in our series is comparable with that obtained currently with navigation systems. In light of this experience, it can be seen that better precision can be achieved for each of the cuts.The accuracy of conventional instrumentation systems is still comparable with that obtained with computer-assisted surgery. The purpose of this study was not to question the benefit of navigation, but to establish a basis upon which progress can be measured. The results enabled a more realistic comparison of the precision of navigation systems and also can be comforting for operators still using conventional ancillaries.

A specific method for accurate and reproducible in vivo knee studies was developed. The femoral knee axis is represented by a straight line which connects lateral and medial markers fixed on the femoral epicondyles. The tibia is represented by three markers. The relative displacements of the femoral knee axis versus the tibia make it possible to determine a knee local frame and to calculate the angles of abduction and axial rotation in the local frame based upon the tibial plateaus.

The aim of this prospective study was to evaluate the objective postoperative laxity and functional results with a minimum follow-up of 10 years (mean 11.7 +/- 2 years) in chronic anterior knee instability treated by ACL reconstruction associated to a lateral extra-articular plasty.138 patients of a mean age of 27.8 +/- 8.5 years had been operated. Delay between injury and operation was 4 +/- 4.8 years. The surgical "Mac Injones" procedure used a free autologous patellar tendon graft with a bone-to-bone fixation, supplemented by a lateral extra-articular plasty using a strip of quadriceps tendon as a direct prolongation of the graft of the patellar tendon and patella itself. A rehabilitation program aimed to an early recovery of a complete range of motion. Anterior laxity had been measured before and after operation using two instrumented methods, KT-1000 and stress-radiography (at 20 degrees of flexion with a 9 kg load applied at the distal part of the thigh) with measurements of the displacement in medial and lateral compartments. Tunnel positioning was appreciated radiologically. Function was evaluated using the International Knee Documentation Committee score (I.K.D.C.).Elongation of the reconstructed ligament occurred mainly during the first 6 month, but was independent from early full range of motion recovery. Laxity was stabilized after one year. The final laxity gain of the medial compartment was 62 per cent and for the lateral compartment 77 per cent. The pivot shift test was negative in 66 per cent, grade 2 in 4 per cent, grade 1 in 30 per cent. Functional results were excellent and good (A and B) in 60.4 per cent and 76.7 per cent returned to sports activity. 12 reconstructed ligaments reruptured. Arthritis was the cause of poor results in other cases (13.8 per cent).Lateral extra-articular plasty is unable to better control translation of the medial compartment than isolated anterior cruciate ligament reconstruction, but laxity of the lateral compartment was minimized and the pivot shift test also. Incorrect position of the anterior cruciate ligament was correlated with poor results.This documented study on laxity of the two compartments confirms the interest of each type of reconstruction, in particular extra-articular plasty when made with quadriceps tendon and so doing, preserving the iliotibial-band for the control of varus stability.

We retrospectively evaluated the anterior talo fibular ligament and the tarsal sinus of 17 patients who had complained of chronic ankle external instability. This study based on both surgery and CT-arthrography findings shows the pathologic or normal aspects of the talo-fibular anterior ligament (normal, lax, fibrosis residue, ruptured). It confirms the good anatomic analysis of the tarsal sinus, in particular the anterior talo-calcaneal interosseous ligament and the search for fibrosis. We underline that capsular distension due to subtalar laxity is not detected with medical imaging. Compared with surgery (all patients), CT arthrography demonstrated the different aspects of the anterior talo fibular ligament injuries (normal, lax, discontinuous).

The aim of this study was to evaluate postoperative evolution of anterior laxity, in order to know at what time the elongation of the reconstructed anterior cruciate ligament (ACL) begins to develop after surgery, and if there were any correlations with recuperation of knee flexion or extension. The second purpose of this study was to compare two series of patients operated on by two different procedures for a long standing ACL rupture.Two series of patients were compared: group I (60 cases), had an ACL reconstruction using a free autologous patellar tendon graft with a bone-to-bone fixation, supplemented by an external extra-articular plasty with a strip of quadricipital tendon as a direct prolongation of the graft of the patellar tendon and patella itself. "Mac InJones", and group II (50 cases), had a reconstruction with a similar transplant, but still attached on the tibia and with a fibrous fixation through the femoral condyle and the Gerdy's tubercule (modified "Marshall-Mac Intosh"). Anterior laxity was measured using two instrumented methods; first, Medmetric knee arthrometer (KT-1000), before and after operation, then each month later during the first 6 months and yearly. On the other hand, a personal stress X-ray protocol (at 20 degrees of flexion and with application of a 9 kg load at the distal part of the thigh), was made before operation, 6 months later, and yearly during 8 years. The laxity of both medial and lateral compartments of the knee were separately measured. Laxity was studied in parallel with the recuperation of knee flexion and extension during a rehabilitation program without any limitation in both directions.During a period of 3 months, the laxity was arthrometrically inferior to the normal knee in the two groups, and appeared progressively. Laxity was independent from early recuperation of full range of flexion and extension. The elongation of the reconstructed ligament was showed to develop during the first 6 months and less during the following 6 months. Better results were found for group I during the earliest period with the Medmetric arthrometer, but there was no difference between both groups after 1 year and 2 years. With dynamic radiography, laxity was higher than indicated by KT-1000, and results were better for group I. Laxity was stabilized after one year and the results were still good after 8 years.KT-1000 showed a great interest for measurement of the compliance index (difference between laxity at 89 newtons and 69 newtons of traction), and can be used without any inconvenient for patients. Stress radiographs may be used for yearly controls. The radiographic method had better accuracy than KT-1000 and gave precise laxity measurements of the medial and lateral compartments of the knee. The laxity of the medial compartment showed to have a good prognostic value.Evolution of laxity is more favourable in group I with bone-to-bone ligament fixation. Recovering early and complete flexion and extension is not prejudicial for the ligament. Laxity developed between 3 and 6 months and less between 6 and 12 months. KT-1000 is able to detect laxity during early postoperative period. Dynamic radiographs are more precise to control laxity year after year. Informations concerning the two compartments of the knee are of great interest to compare different procedures and to improve new surgical techniques.

The purpose of this study was to compare the functional results obtained when an external extra-articular plasty was added to an anterior cruciate ligament (ACL) reconstruction using an autologous bone tendon-bone patellar tendon graft.The authors analyzed two consecutive series of 60 and 50 patients operated by the same surgeon for a chronic rupture of the anterior cruciate ligament, one by reconstruction of the cruciate ligament with a free graft of the patellar tendon supplemented by an external extra-articular plasty made with a quadriceps tendon graft and the second with an isolated free patellar tendon graft. Anterior laxity was measured before and after surgery, by dynamic X-rays and by the Medmetric KT-1000 arthrometer. Functional results were evaluated four years after operation, with the French A.R.P.E.GE score based on sport activity level and intensity.Anterior laxity was not different before operation in both groups and there was no difference between males and females. Medmetric KT-1000 arthrometer showed the same negative differential laxity immediately after surgery in both groups and the same evolution during the first 4 years, without any significant difference on laxity on the middle aspect of the knee. Radiological results were different. After a 4 years follow-up, anterior laxity did not show significant difference on the medial compartment of the knee (5.3 +/- 2.3 mm and 5.5 +/- 1.7 mm), but there was a significant minor laxity in the lateral compartment for the lateral extra-articular plasty group (11.0 +/- 2.3 mm against 14.8 +/- 3.8 mm)(p = 0.002). Functional results and sport activity were similar in both groups. Examination showed 4 positive pivot shift tests (2 "sliding" and 2 positive) in the group with extra-articular plasty, even though 8 positive pivot shift tests in the isolated ACL group (5 "sliding" and 3 positive) were found.This study, as well as five others studies found in literature, was not randomized. In all these series, the surgical techniques, the rehabilitation programs and the functional score evaluation were too different to allow any pertinent comparison. Extra-articular plasty helps to control the laxity of the lateral compartment of the knee which is incompletely controlled by ACL reconstruction, particularly in chronic cases. This is proved by radiological measurements and pivot shift tests. Jensen in 1983, about 205 patients with a 4 year follow-up and Noyes, which used an allograft patellar tendon, found an advantage to do extra-articular plasty. But Strum (in 1989), as O'Brien (in 1991) and Roth (in 1987), did not found any advantage with extra-articular plasty.It is therefore obvious, after a four-year follow-up, that extra-articular supplementation presents an advantage for reconstruction of the ACL. by a free graft of the patellar tendon in chronic cases. Further randomized study will confirm that isolated ACL reconstruction is possible in some well defined categories of anterior laxity.

Posterior lumbar interbody fusion (PLIF) as described by Cloward, with laminectomy of the entire separate neural arch in spondylolisthesis, is a difficult operation. The purpose of this study is to evaluate the results of PLIF with autologous bony graft, without reduction or instrumentation in grade I and II spondylolisthesis.The authors report the results of a series of 36 cases of spondylolisthesis (out of a series of 160 cases) operated on with PLIF, after a minimum of 10 years of follow-up (mean: 11.8 years, 10-16 years). 9 patients were lost for follow-up, 27 had been examined clinically and radiologically. 19 males and 8 females. Mean age 29.6 years (14 to 50). The series consisted in 24 lumbo-sacral disc and 3 L4-L5 disc fusion. Before operation, 25 patients suffered backache and 20 had sciatic. Mean preoperative listhesis according to Boxall was 29 per cent.PLIF had been done with autologous bony graft and neural decompression without reduction. The thickness of the space had been restored with special progressive distractor. Postoperative back cast was used during 6 months.Postoperative nerve roots complications occurred in 4 cases and were regressive within 3 months. Results were excellent in 17 cases, good in 7 cases and poor in 3 cases. Patients returned to work after 9.8 months (13.6 months for heavy work). 26 patients had solid tomographic interbody fusions. No additional subluxation was noted. In 10 per cent of the cases the graft was partially crammed. In 7 cases a degenerative aspect of the upper disc was noted (symptomatic in 6 cases). The sagittal balance of the spine evaluated with a specific index showed persistent abnormality in 50 per cent of the cases but PLIF brought a significant improvement in 26 per cent.The rate of fusion is better than in series using bony allografts and better than in series using anterior interbody fusion. The analysis of the adjacent discs shows that it is not necessary to extend fusion to the upper disc. Instrumentation had not been used in this series but a cast seems to be indispensable. Instrumentation with plates and pedicular screws should be able to give more stability but is often responsible of iatrogenic lesions at the articular facets.This study confirms the good results obtained by PLIF with nerve roots decompression in spondylolisthesis. Fusion is stable and does not accelerate degenerative lesion of the upper disc.

Nitrogen ion implantation is the most efficient way to improve the wear resistance of Ti6A14V femoral heads. Nevertheless, even if this process is now overcome in the case of plane targets, the spherical geometry of the prosthetic component make the ion implantation hard to control in terms of homogeneity and chemical reaction inside the substrate. Therefore we developed in our laboratory a process that should lead to an improvement of this surface treatment. Considering this process, we are studying the influence of the implantation parameters upon the quality of the results. The implanted samples are analysed by means of RBS, ESCA, GDS, X-Ray and SEM.

The authors describe a new surgical technique of tendo achilles reconstruction using bone tendon plasty from the patellar tendon, for rare chronic ruptures of the Achilles tendon flush within its calcaneal insertion, with distal loss of substance, requiring bone fixation.The two step operation was carried out either in lateral or ventral decubitus (the latter two involving repositioning the patient): 1) Plasty harvesting. By a short anterior approach, we harvested either a strip of patellar tendon (10 mm wide) with a piece of tibia tuberosity or a strip of rectus femoris tendon (10 mm wide, up to 10-15 cm long) with a piece of patellar bone, in cases with a greater loss of substance. Tendo achilles reconstruction: following resection of fibrous tissue, and drilling of a blind calcaneous tunnel, the bone plasty is fitted into the calcaneous with interference screw for safety, the two tendon ends are superposed and sutured. The patient is placed in a cast for two months.Two patients (1 thirty-eight year old sportsman, 1 thirty-seven year old woman) were treated with a good morphological and functional outcome at two years.This new technique is compared with other available solutions: triceps plasty, other local tendon plasties, artificial plasties, It met the two criteria for these unusual ruptures: solid calcaneous fixation, no skin damage.

Most authors agree on the importance of medial meniscus preservation in the case of A.C.L. reconstructive surgery. The purpose of this study was to analyze the anatomical results of sutures of medial meniscus tears by the means of arthrography.Medial meniscus 42 sutures for peripheral tears at the posterior horn (length between 10 and 50 mm, 70 per cent greater than 20 mm) had been performed through an open procedure using a posterior approach. The average age of the patients was 24 years (17-54) with a clear male predominance (64 per cent). The average age at the time of injury was 22 years, 6 months.The patients were operated on by the same surgeon, with the same technique. Resorbable sutures were used spaced every-3 mm, and tightened outside the joint. The A.C.L. was reconstructed by a bone-patellar tendon-bone technique (modified K.G. Jones). A first series of 13-patients were no weight bearing allowed for 6 weeks post-operatively. A second series of 29 patients were allowed immediate partial weight bearing. All the patients were permitted active flexion. All the patients had been examined with a minimum of 6 months follow-up. They were all controlled clinically (results evaluated with the I.K.D.C. score) and with passive dynamic X rays to measure residual laxity. 32 patients had an arthrogram before the operation in the aim to compare with the postoperative arthrogram. 30 patients had an arthrogram after an average of 21 months. 12 patients refused follow-up arthrograms. 9 patients had arthroscopy for pain or effusion.All the patients obtained a range of flexion-between 90 degrees and 110 degrees at 4 weeks. A flexed contracture of 10 degrees was noted in only 1 case. Meniscal functional results were good for 32 cases after a mean follow-up of 4 years and 4 months. Arthrograms in 30 cases showed no residual tear in 19 cases (63 per cent), 3 cases had incomplete healing and 8 cases had failed. The healing was influenced by the size of the tear, its situation near the posterior wall. In the first series (no weight bearing), there were 2 failures for 9 cases and 6 out of 21 in the second series and 3 incomplete healing. There was no correlation between meniscal functional results and functional ligamentous results evaluated with the I.K.D.C. score. 9 patients had an arthroscopy and 7 out of them a meniscectomy (after 17 months 3).This study confirms the possibility of healing following suture of peripheral medial meniscal tears in the case of ACL reconstructive surgery (even if the tear is long). The use of arthrogram, before the operation and for anatomical control after the operation, ensures complete healing (better than M.R.I. for the suture control). Arthrography is certainly a less invasive technique than arthroscopy.

A new clinical test named "The shoulder anterior jerk test" is proposed to confirm the diagnosis of chronic shoulder anterior instability.The test combines of a compression force and a translation force, applied along the arm between the humeral head and the glenoid cavity. In so doing, a subluxation of the humeral head is provoked and it is accompanied with a jerk recognised by the patient as his instability.Three different populations of patients had been studied: Population A: 28 patients operated on for chronic anterior dislocation, uni or bilateral (32 shoulders), had been tested before the operation, without and under anesthesia. Population B: 100 patients without any problem at the shoulder, had been tested before and under anesthesia done for knee or hip surgery. Population C: 100 young sportive athletes with normal shoulder tested without anesthesia.Population A: The 28 patients suffering from shoulder instability had all a positive shoulder jerk test under anesthesia. Without anesthesia the test had been positive only in 10 cases (30 per cent). The jerk is potentially present for all the patients, but it is disturbed by apprehension. Population B: Among the 200 shoulders tested, 26 shoulders (17 patients) had a positive test under anesthesia (13 per cent). 5 had positive jerk test without anesthesia. Population C: 5 among the 200 shoulders tested had a positive jerk test (2.5 per cent) Under anesthesia the test has a sensitivity of 100 per cent, a specificity of 87 per cent, a positive predictive value of 55 per cent and a negative value of 100 per cent. Without anesthesia, the test has a sensitivity of 31 per cent, a specificity of 97.5 per cent, a positive predictive value of 66 per cent and a negative predictive value of 90 per cent.The instability which is shown by the jerk test is in relation with the anterior subluxation of the humeral head in front of the anterior edge of the glenoïd cavity. It reproducts, with a minimal amplitude, the clinical instability which is recognized by the patient. The test is always positive under anesthesia in case of chronic anterior instability, it may confirm pre-operative diagnosis just before the begining of the procedure and may orientate the choice of it. Apprehension is a major obstacle to the research of the jerk, but it is the same with the other classical clinical tests of the shoulder anterior instability.The anterior jerk test of the shoulder is thus a test which is able to prove the diagnosis of an anterior instability. The future will permit to confirm its efficiency and will confirm if the test may differenciate anterior and inferior instability with variation of the abduction, as it has been shown in this preliminary study.

The development of the indications in the arthroscopic surgery of the ankle and the narrowness of this joint impose perfectly adapted portals. Several posterior portals which allow to access to the postero medial corner of the joint have been already described, but are not satisfying. We describe, here, a new postero-medial portal which allows a safe and easy access to the posterior part of the joint.The arthroscopy is performed with a standard arthroscope (30 degrees, 4.5 mm in diameter) and a lateral ankle distractor. The landmark for this portal is the posterior crest of the medial malleolus. Above the posterior tip of the medial malleolus, this crest is directed up and back, then its direction becomes strictly vertical. The new portal is situated there, 5 millimeters behind the crest (generally 2 centimeters above the posterior tip of the medial malleolus). A needle visualized by the anterior portal is helpful to show the right direction for the portal. After skin incision, a forceps is used to widen the portal. Then the instruments or the arthroscope can be introduced. Posterior tibial artery and nerve are protected by the tendons of tibialis posterior and flexor digitorum longus.We have used this portal (instrumentation and arthroscope) in four patients (3 osteochondritis dissecans of the medial part of the talus, 1 loose body) without problem.This portal is safe; it does not intersect the direction of posterior tibial artery and nerve as in the postero-medial portal described by Parisien and avoids in most cases the approach described by Guhl.Because the medial malleolus is more anterior than the lateral malleolus, it allows a larger approach to the posterior part of the joint than the postero-lateral portal. We recommend it for the arthroscopic treatment of all the lesions of the postero-medial part of the joint.

After some considerations on the biomechanical nature of pubic pain, the authors present a series of 17 leading athletes (14 professional football players, 1 marathon runner, 1 weight-lifter and 1 French boxer), complaining of this disorder for at least one year and refractory to conservative treatment, surgically treated with the Nesovic technique and evaluated after an average follow-up period of two years (18-30 months).

Fifty-one knees were reviewed out of 53 which had been operated on (between 1981 and 1991) for instability due to a long-standing rupture of the anterior cruciate ligament (A.C.L.), associated with medial arthritis related to a varus deformity. They had undergone a reconstruction of the cruciate ligament using the patellar tendon (5 cases had received an artificial ligament) and a high tibial osteotomy. In 80 per cent of cases this was an opening osteotomy with interposition of a heterologous bone graft, and in 39 cases it was a closing osteotomy. The average age was 37 +/- 6 years. The oldest patient was 58 years old. 80 per cent of cases were men and 88 per cent of the patients practised sport on a regular basis at the time of the accident. The average delay before surgery was 9.5 years. Almost all the patients has already undergone a medial meniscectomy and there were deep cartilaginous lesions and the bone was exposed in 50 per cent of cases. 28 knees were reexamined after a follow-up of over 4 years. Based on the ARPEGE score the results on pain and stability were good. Return to sport has been possible for 43 per cent of patients. Pivot shift, which was constant before surgery (grade 2 or 3), disappeared in 20 cases and was estimated at grade 1 in 8 cases (of which 6 had suffered a rupture of the graft). For the 20 cases in which the reconstruction of the A.C.L. had held, the average anterior radiological subluxation was 4.3 +/- 3.2 mm (from 2 to 14 mm) and the average gain after surgery was 6.7 +/- 3.7 mm (from 2.5 to 18 mm). The femoro-tibial angle went from an average of 6 degrees of varus to 3 degrees of valgus. The opening osteotomy was more precise for correction in the frontal plane. A large valgus (over 3 degrees) was not desirable and a hypercorrection was occasionally difficult to accept by relatively young patients who are likely to take up sport again. The osteotomy often involuntarily modified the normal posterior tibial plateau slope (especially closing osteotomy). A backwards increase of the tibial plateau slope is a factor which increases the anterior subluxation of the femur on the tibia. This is confirmed before and after surgery. It seems preferable to decrease the tibial slope during the osteotomy in order to protect the A.C.L. reconstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Three base alumina ceramics with dispersoids: monoclinic zirconia alumina (A5Z), tetragonal zirconia alumina (A20Z) and aluminalon (Aa20) have been investigated because of their improved mechanical properties with reference to pure alumina (AI203). Bending strength and fracture toughness are twice higher than alumina for the most toughened. These two parameters were measured by four-points bending tests after 1 week, 1, 2, 3, 6, 12 months of non loaded in vivo aging in wistar rats. They showed a little decrease for AI203 and Aa20 and a total stability for A5Z and A20Z even after one year. For tribologic study of the ceramic/polyethylene combination, cylinder against plane and pin on flat tests were conducted on an alternative movement with hip parameters of speed and load in presence of ringer solution. For the most representative test (pin on disk), the friction coefficients were nearly the same for all materials but UHMWPE wear volume was twice lower against A20Z than against AI203. A20Z/UHMWPE combination would be very interesting as new friction couple for total hip arthroplasty. Further studies are currently conducted.

Objectifs pedagogiques Rappeler l’histoire naturelle de l’osteochondrite dissequante du genou en fonction de l’âge. Definir le bilan lesionnel et les criteres pronostiques en fonction des nouvelles avancees therapeutiques. Rappeler l’importance de l’imagerie dans la prise en charge.