Background: The medial patellofemoral ligament (MPFL) is the primary stabilizer of the patellofemoral joint. Its reconstruction has been recommended in adults over the past decade after recurrent patellar instability. The purpose of this study was to assess outcomes after MPFL reconstruction in children and adolescent and to prospectively evaluate reconstruction by computed tomography (CT scans) before and after surgery.

Materials and Methods: Thirteen consecutive patients (5 boys and 8 girls)(13 knees) underwent a double bundle MPFL reconstruction with hamstring tendon autograft (gracilis:6, semitendinosus: 7) for patellar instability. A bone femoral fixation with interference screw in a tunnel was associated with patellar fixation according to Fithian in mature knees, and a soft tissue procedure was performed in skeletally immature knees. In 5 knees the MPFL reconstruction was isolated while it was associated with medialization and distalization of the tibial tubercle in 8 knees. The mean age at time of surgery was 14.4 years (range, 9.6– 16.5). Patients were evaluated preoperatively and postoperatively by physical, radiological and CT Scans examination and subjectively with the IKDC and Kujala questionnaires. During CT scans with knee fully extended and the quadriceps contracted or relaxed, the patellar tilt angle was assessed. In cases where tibial tubercle was mobilized, the tibial tubercle-trochlear groove (TT-TG) distance was measured pre and postoperatively.

Results: No recurrent episodes of dislocation or sub-luxation were reported after 10.5 months (range, 3–23) follow-up after surgery. Mean Kujala score was of 90.2 (range, 84–99) at latest follow-up. For all patients the moving patellar apprehension test was positive before and negative after surgery. A firm end point to lateral patellar translation was noticed in all patients at latest follow-up. Objective assessment with CT noted that the patellar tilt on relaxed quadriceps was significantly improved from 28° preoperatively (range, 16–41) to 16° at follow-up (range, 7–32). The patellar tilt on contracted quadriceps was significantly improved from 35° preoperatively (range, 21–52) to 24.6° at follow-up (range, 11–48). In the specific subgroup, the TT-TG distance decreased preoperatively from 15.4 mm (range, 12–19) to 9 mm postoperatively (range, 2.9–14.8).

Conclusion: MPFL reconstruction in children and adolescent is an effective procedure. The patellar tilt was efficiently improved by MPFL reconstruction and these results were correlated with Kujala score. Mid and long term results are still to be evaluated.

Purpose of the study: There remains some debate on the proper treatment of congenital dislocation of the patella in children and adolescents. Ligament-periosteum transfer (green-stick method) is a technique adapted for pediatric patients which realigns the distal extensor system.

Material and methods: Between 1979 and 2000, 36 children (51 knees) were treated with this method described by Grammont. Section of the lateral wing and medial capsulomyoplasty were associated in all procedures. Other complementary procedures used as needed included lengthening of the quadriceps, trochleoplasty, and quadriceps release. Mean age at surgery was 11 years (range 5–15 years). All patients were reviewed at bone maturity with a mean follow-up of 7.5 years for functional (IKC criteria) and radiographic assessment. A computed tomography and/or magnetic resonance imaging was obtained preoperatively and at last follow-up to assess TAGT, patellar height, trochlear angle, femoral anteversion, external tibial torsion, and knee rotation. Tibial slope was specifically studied to assess the possible epiphysiodesis effect.

Results: Two groups of patients were distinguished: congenital dislocation of the patella (persistent or usual) and objective patellar instability. Functional outcome was good in 74% and 87% of the knees. There were eight cases of recurrent dislocation: five knees were operated on with good outcome. The trochlear angle was improved in both groups, more significantly in the congenital dislocation group. There was one case of an inverted tibial slope (−2°) and two cases of cancelled slope.

Discussion: Our functional results are in agreement with earlier reports (Grammont, Bensahel, Langeskiold) but comparison is hindered by the heterogeneous nature of the different cohorts. Radiographically, we observed that trochlear remodeling, a sign of good stability, is better if the operation is performed early (before the age of ten years). On the contrary, in adolescents with major patellar instability, complementary trocheloplasty should be performed in addition to the recentering procedure. We observed that a small tibial slope became smaller in eleven knees in comparison with the nonoperated knee and in comparison with the preoperative slope for the bilateral cases. There appears to be a discrete epiphysiodesis effect but with no functional consequence.

Conclusion: We propose a classification of congenital dislocation of the patella in children. The ligament-periosteum transfer technique, associated with other procedures as needed, enables stabilizing the extensor system and a normal trochlear angle if surgery is performed at a young age. Remodeling of the tibial tubercle may result from transient disruption of the vascular supply.

Purpose: Over recent years, several authors have estimated that the distal femur presents an epiphyseal torsion which can be measured intraoperatively or on the preoperative scan. This measurement does not however take into account the dynamic mechanical axis, particularly the mechanical axis at 90° flexion when walking. We used a computer-assisted navigation system (Ortho-pilot®) to attempt to measure femoral rotation by dynamic gonometry in extension and 90° flexion before and after implantation of a total knee arthroplasty.

Material and methods: We recorded the preoperative (Rx) and intraoperative (Orthopilot) HKA in extension and in 90° flexion before and after implantation of 50 total knee prostheses (Search®, Aesculup, AG, Tuttlingen) and again postoperatively (Rx). The series included 19 knees with genu valgum (mean HKA 187.36±5.4°, range 181°–203°), 30 knees with genu varum (HKA 169.2±4.11, range 160°–176°), and one normal axis knee.

Results: The radiographic values obtained preoperatively were confirmed by Orthopilot, respectively 186.68±5.25° and 169.76±3.84° in extension. At 90° flexion, HKA was 178.63±5.7° before implantation for genu valgum giving a significant varus due to lateral opening during flexion,and 171.6±4.15° for genu varum, showing persistence of varus. After implantation of the total knee prosthesis, the values were as follows. For the genu varum: HKA in extension 180.57±0.82° and HKA in 90° flexion 176.86±2.55° giving a mean residual varus of 3.16±2.86° (from 4–8° varus) without external rotation of the femoral implant. For genu valgum, HKA in extension was 179.60±0.92° and HKA in 90° flexion was 176.1±3.23°, giving a mean residual varus of 3.26±2.86° (0–10° varus), recalling that in the event of genu valgum we impose external rotation due to the frequent hypoplasia of the lateral condyle.

Discussion: Orthopilot-assisted implantation of total knee prostheses provides new information concerning dynamic gonometry, particularly the varus or valgus in flexion, which corresponds to measuring natural external or internal rotation. Measuring epiphyseal torsion of the distal femur with classical methods does not take into account the global rotation of the femur which is often an external rotation (up to 8° for genu varum). Systematic implantation of the femoral component in external rotation raises the risk of increasing considerably the varus forced to the implant during flexion.

Purpose: The purpose of this study was to compare, at ten years follow-up, the clinical and radiological results obtained in two series of patients who underwent patellar tendon ligmentoplasty for anterior cruciate ligament tears. One series was operated in an acute setting (before 45 days) and the other for chronic lesions.

Material and methods: In 1986 and 1987, we performed patellar ligamentoplasty for anterior cruciate ligament tears in 230 knees. Mean delay to surgery was ten days for 77 knees (53 reviewed with clinical and radiological evaluation and 12 with questionnaires, i.e. 84%). For 153 knees surgery was performed for chronic lesions (107 reviewed with clinical and radiological evaluation and 12 with questionnaires, i.e. 77%). The IKDC chart was used to assess outcome with KT 2000 measurements on the loaded images.

Results: There was a significant difference between the two series for: overt meniscal tears at the time of surgery (58% in the chronic series and 11% in the acute series, p < < 1%); osteoarthritic (26% chronic versus 6% acute, p < 1%); overall IKDC score (96% for acute versus 84% for chronic, p < 3%). The same was true for subjective assessment (normal for 95% of the acute knees versus 65% for the chronic knees) and for rate of recurrent tears (2% for acute and 9% for chronic). There was no significant difference between the series for clinical signs (pain, swelling, apprehension), mean residual laxity as measured by KT 2000, although it was greater for the chronic knees (+2.6%) than for the acute knees (+2.3%). Permanent flexion was not significantly different between the series (31% for chronic and 28% for acute) although the reason was different since for the chronic series, subsequent meniscectomy was necessary.

Conclusion: Patellar ligamentoplasty performed in an acute setting provides better clinical and radiological outcome. It stabilises the knee better before possible development of a meniscal lesion that may precipitate osteoarthritis.

Purpose: The purpose of our study was to evaluate, in a context of laxity, the incidence of meniscal lesions and their treatment on the osteoarthritic evolution after more than ten years. In 1986 and 1987, we operated 230 knees with tears of the anterior cruciate ligament using a patellar graft. Among these knees, 184 (80%) were reviewed clinically and radiographically for this study.

Material and methods: Ninety patients (49%) had healthy menisci at the operation and did not have a secondary meniscal procedure; 94 patients (51%) had a meniscal procedure before, during or after the plasty. Among these, 13 (14%) had had an earlier meniscectomy, 18 (19%) had had meniscectomy at the time of the plasty (two revisions), 35 (37%) had had sutures (five secondary failures), ten (11%) had had a long injury left in place (four revisons), and 18 (19%) with normal knees at the time of the plasty had a secondary meniscectomy.

Results: We compared the radiological results in these different populations (osteoarthritis with remodelling compared with normal images). There was a significant difference between the population with normal knee images and the population with meniscal lesions irrespective of the time of treatment (prior meniscectomy, concomitant meniscectomy and plasty, healthy menisci at the time of plasty but secondary meniscectomy). There was no significant difference between the knees with normal menisci and those with sutured menisci.

Conclusion: Saving the meniscus has a major effect on the radiological evolution of the knee. Thus isolated meniscectomy should not be performed for laxity in young patients; meniscal lesions should be sutured at the time of ligamentoplasty.