Mobile-bearing insert translational and rotational kinematics in a PCL-retaining total knee arthroplasty.

INTRODUCTION: Total knee prostheses with a mobile-bearing insert were developed to provide nonconstrained joint range of motion while reducing friction forces. The purpose of this study was, based on weightbearing X-rays, to evaluate the mobility of the polyethylene tibial insert in relation to the femoral and tibial components. We studied the results of a cementless total knee arthroplasty (TKA) retaining the posterior cruciate ligament (PCL), with a mobile-bearing platform in rotation and anteroposterior translation (Innex Anterior-Posterior Glide, Zimmer) with a mean 23-month follow-up duration after surgery. HYPOTHESIS: Both anterior-posterior tibiofemoral translation and intraprosthetic axial rotation occur between the mobile polyethylene insert and the tibial endplate. MATERIAL AND METHOD: In a series of 51 primary TKA, the three-dimensional (3D) kinematics of the femoral, tibial, and mobile insert components were determined using a computerized matching system between the prosthetic 3D models and the radiographic images of the implants on three lateral follow-up weightbearing knee X-rays: films were taken in full extension, at 45 degrees flexion, and at maximum flexion. RESULTS: There was a statistically significant increase in the internal rotation of the mobile tray with flexion, (up to a mean -3+/-3 degrees between the femoral box and the mobile tray [p<0.0001] and up to a mean -5+/-7 degrees between the tibial tray and the mobile tray [p<0.0001]). The mobile tray did not translate in relation to the tibial endplate from extension to 45 degrees flexion (0+/-2 mm [range: -5 to 6 mm]). However, from 45 degrees to maximum flexion, a statistically significant mean 1+/-2 mm (range: -2 to 9 mm) of anterior translation (p<0.0001) was found. DISCUSSION: The extent of insert mobility varies from one study to another. Some have reported relatively limited mobility stemming from a superior surface that is not highly congruent, (thus allowing anterior-posterior and mediolateral translation through gliding of the femur in contact with the insert). Other studies have reported mobile-bearing tray mobility in relation to the tibial endplate and minimal rotation at the femoral component level. In this series of PCL retaining TKA with a mobile-bearing platform, the mobile-bearing platform showed a progressive increase in internal rotation during flexion. Most of this rotational mobility occurred between the mobile platform and the tibial endplate, confirming our hypothesis. However, with flexion, the femoral component increased its mobility relatively to the platform. During flexion, an anterior-posterior translation occurred between the femoral implant and the tibial insert, and between the tibial insert and the tibial endplate, but the direction of the mobile tibial insert translation remained unpredictable with this nonconstrained implant design used. LEVEL OF EVIDENCE: Level IV. Prospective non-controlled therapeutic study.

Kinematics of a cementless mobile bearing posterior cruciate ligament-retaining total knee arthroplasty.

Mobile bearing (MB) total knee arthroplasty (TKA) was developed to provide low contact stress and unconstrained joint motion. We studied a consecutive series of 41 knees with mobile-bearing, posterior cruciate-retaining (CR) TKAs to determine if kinematics resembled normal knees or if kinematics changed over time. Patients were studied at 3 and 21 months average follow-up with weight-bearing radiographs at full extension, 30 degrees flexion and maximum flexion. Shape-matching techniques were used to measure TKA kinematics. Implant hyperextension, maximum flexion and total ROM increased with follow-up. Tibial rotation and condylar translations did not change with time. The medial condyle did not translate from extension to 30 degrees, but translated 5 mm anteriorly from 30 degrees to maximum flexion. Lateral condylar translation was 3 mm posterior from extension to 30 degrees, with no translation from 30 degrees to maximum flexion. Tibiofemoral kinematics in CR-MB-TKAs were stable over time, but did not replicate motions observed in healthy knees. The mobile tibial insert showed rotation and translation at both follow-up examinations, but the patterns of translation were not predictable.

[Patellar fracture after anterior cruciate ligament reconstruction using a bone patellar tendon bone transplant: a comparative study of two harvesting techniques]. / Fracture de la patella après prélèvement os-tendon patellaire-os pour ligamentoplastie de reconstruction du ligament croisé antérieur : incidence du type de prélèvement.

PURPOSE OF THE STUDY: We studied the incidence and the impact of patellar fracture after anterior cruciate ligament (ACL) reconstruction, comparing two harvesting techniques. MATERIAL AND METHODS: 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. RESULTS: 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. DISCUSSION: The fact that the Mac InJones technique does not involve a transversal cut would apparently prevent secondary fracture.

[Results of self-centering patellofemoral prosthesis: a retrospective study of 57 implants]. / Résultats de la prothèse fémoropatellaire autocentrique: à propos d'une série continue de 57 prothèses.

PURPOSE OF THE STUDY: 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. MATERIAL AND METHODS: 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%). RESULTS: 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). DISCUSSION: 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. CONCLUSION: 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.

Comparative study of knee anterior cruciate ligament reconstruction with or without fluoroscopic assistance: a prospective study of 73 cases.

INTRODUCTION: Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament (ACL) reconstruction. We used an original system of computer assisted surgery (CAS). The system, based on fluoroscopic guidance combined with special graphical software of image analyzing, showed to the surgeon, before drilling, the recommended placement of tibial and femoral tunnel centers. We compared the first anatomical and clinical results of this procedure to the usual one single incision technique. MATERIALS AND METHODS: We conducted a prospective study on 73 patients; 37 patients were operated on with CAS and 36 without CAS, by the same senior surgeon. The mean age was 27 years for both groups. Every patient was reviewed at an average of 2.2 years (range 1-4.5) by an independent observer, using IKDC scoring system, KT-1000, and passive stress radiographs. RESULTS: Time between ACL rupture and reconstruction averaged 30 months for both groups. CAS needed 9.3 min extra surgery time. Clinical evaluation was graded from A to C as per the IKDC scoring system: 67.6% A, 29.7% B, 2.7% C with CAS; and 60% A, 37.1% B, 2.9% C without CAS. IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS. Pre operative KT-1000 maxi manual differential laxity averaged 7. At revision time, all the patients after CAS had a differential laxity less than 2 and 97.7% without CAS. Stress X-rays differential laxity averaged 2.4 mm with CAS and 3 mm without CAS. The area of dispersion of the tunnels' center was smaller on the femoral side using the CAS method. There was no statistically significant difference between both groups using IKDC score, KT-1000 and passive stress radiographs. CONCLUSIONS: The CAS method provided a more accurate and reproducible tunnels placement without clinical significant effect.

Effects of radiograph projection parameter uncertainty on TKA kinematics from model-image registration.

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.

[Anterior cruciate ligament revision: analysis and results from a series of 74 cases]. / Les reprises de ligamentoplastie du ligament croisé antérieur: analyse et résultats d'une série de 74 cas.

PURPOSE OF THE STUDY: 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. MATERIAL AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

[Analysis of meniscal lesions accompanying anterior cruciate ligament tears: A retrospective analysis of 156 patients]. / Lésions méniscales constatées lors de la reconstruction du ligament croisé antérieur: siège et nature dans une série continue de 156 patients.

PURPOSE OF THE STUDY: 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. MATERIAL AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

[Axial lower limb alignment and knee geometry in patients with osteoarthritis of the knee]. / Analyse segmentaire de la déformation frontale dans les gonarthroses fémoro-tibiales latéralisées.

PURPOSE OF THE STUDY: We conducted a retrospective radiographic study to identify and quantify medial and lateral misalignments in candidates for total knee arthroplasty. MATERIAL AND METHODS: 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. RESULTS: 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 (p<0.01). Ankle inclination followed tibial varus (p<0.01). 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 (p<0.001). Tibial varus was greater with greater femoral valgus (p<0.01). In both groups, the HKS angle was smaller with greater femoral valgus. DISCUSSION: 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. CONCLUSION: 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.

[One-stage reconstruction of the two cruciate ligaments with a single autogenous graft from the extensor system: techniques and results of 25 chronic cases]. / Reconstruction simultanée des 2 ligaments croisés par un transplant autogène unique: technique et résultats à propos de 25 laxités chroniques.

PURPOSE OF THE STUDY: Chronic tears of both cruciate ligaments are rarely encountered. Management practices have varied. One-stage reconstruction of both ligaments using arthroscopically implanted allografts was proposed starting in 1996 for such chronic laxity but only 44 cases have been reported in six papers mixed in with recent cases raising very different problems. Treatments using allografts or autogenous grafts or both implanted arthroscopically have often been combined with open surgery. We report a retrospective analysis of 25 knees treated with the same technique from 1983 to 2004: reconstruction with a single transplant taken from the extensor system. MATERIAL AND METHODS: A 30-cm lenght patella tendon-patella-quadriceps tendon graft was harvested. The patellar block was fixed in a hole drilled under the tibial spine, the patellar tendon replacing the posterior cruciate ligament and the quadriceps tendon passing through the lateral condyle and replacing the anterior cruciate ligament before implantation on Gerdy's tubercle, this also creating an extra-articular plasty with the same implant. Medial, lateral and posterior plasties were performed, depending on the radiographic assessment of laxity. Twenty-five knees with major laxity and instability were operated on, including 14 in two-stage operations. The differential anterior drawer was 10+/-3 mm medially and 9+/-5 mm laterally. The posterior drawer at 70 degrees was 15+/-4 mm medially and 10+/-6 degrees laterally. The total anteroposterior laxity of the medial compartment was 29 mm, it was 30 mm for the lateral compartment. Lateral laxity was considered major (>10 degrees ) in 17 knees and medial laxity in 7. Lateral and medial laxities were associated in eleven knees. Hyper-extension was very severe in five knees. RESULTS: Functional outcome at mean 6.5 years follow-up (range 1-21) was satisfactory (except in three knees) allowing renewed occupational activity. Resumption of sports activity was less marked and none of the knees was in IKDC class A, corroborating results in the literature. Anatomic outcome was assessed on the radiological drawer decrease which was modest, mean gain in the anterior drawer measuring 4 and 5 mm in the medial and lateral compartments and mean gain in the posterior drawer measuring 5 mm medially and 3 mm laterally. Peripheral laxity was corrected for best. DISCUSSION: Classically, one or other of the cruciate ligaments is repaired, sometimes both, but in a two-stage procedure associating two different methods and autogenous tendon grafts. One-stage reconstruction of both cruciate ligaments with a single autogenous graft and a wide approach has not led to any complications. One-stage reconstruction using this technique has several advantages: one anterior incision, single transplant which also enables lateral plasty, short immobilization time with rapid rehabilitation.

[Accuracy of total knee replacement bone cuts using a conventional ancillary system: 300 Innex total knee arthroplasties]. / Précision des coupes osseuses dans l'arthroplastie totale du genou à l'aide d'un ancillaire conventionnel: trois cent poses consécutives de prothèses Innex.

PURPOSE OF THE STUDY: 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. MATERIAL AND METHODS: 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). RESULTS: 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). DISCUSSION: 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. CONCLUSION: 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.

[Intra-articular reconstruction of the anterior cruciate ligament with and without extra-articular supplementation by quadricipital tendon plasty: seven-year follow-up]. / Influence d'une ligamentoplastie extra-articulaire latérale sur les résultats de la reconstruction du ligament croisé antérieur avec le ligament patellaire avec 7 ans de recul.

PURPOSE OF THE STUDY: 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). MATERIAL AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Knee instability after injury to the anterior cruciate ligament. Quantification of the Lachman test.

We have measured anterior and posterior displacement in 563 normal knees and 487 knees with chronic deficiency of the anterior cruciate ligament (ACL). We performed stress radiography using a simple apparatus which maintained the knee at 20 degrees of flexion while a 9 kg load was applied. There was no significant difference in posterior translation dependent on the condition of the ACL. Measurement of anterior translation in the medial compartment proved to be more reliable than in the lateral compartment for the diagnosis of rupture of the ACL, with better specificity, sensitivity and predictive values. We have classified anterior laxity based on the differential anterior translation of the medial compartment and identified four grades in each of which we can further distinguish four subgrades for laxity of the lateral compartment. Within each of these subgroups, either internal or external rotation may dominate and sometimes there is a major translation of both compartments. Radiological evaluation of displacement of the knee in 20 degrees of flexion provides conclusive evidence of rupture of the ACL. A detailed study of pathological displacement is the basis for a classification of laxity. It is then possible to decide for each type of laxity, the surgical treatment which is specifically adapted to the lesion, and to define a reference value for judging outcome.

Achilles tendon repair using a bone-tendon graft harvested from the knee extensor system: three cases.

The authors describe a new surgical technique of Achilles tendon reconstruction using bone-tendon graft from the knee extensor system. This technique is for those unusual cases of neglected or partial Achilles tendon rupture with distal tendon-substance loss at calcaneal insertion level, requiring transbone plasty fixation. Three cases are reported; the first two, followed up over a 5-year period, had excellent functional, morphological, and clinical outcomes. This new technique is compared with other available solutions: triceps plasty, other local tendon plasty, artificial plasty, and allograft.

[The results after 10-16 years of the treatment of chronic anterior laxity of the knee using reconstruction of the anterior cruciate ligament with a patellar tendon graft combined with an external extra-articular reconstruction]. / Les résultats après 10 à 16 ans du traitement de la laxité chronique antérieure du genou par une reconstruction du ligament croisé antérieur avec une greffe de tendon rotulien associée à une plastie extra-articulaire externe. A propos de 138 cas.

PURPOSE OF THE STUDY: 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. MATERIAL AND METHODS: 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.). RESULTS: 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). DISCUSSION: 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. CONCLUSION: 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.