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: Prenatal screening and search for risk factors has lead to early diagnosis of congenital hip dysplasia. The percent of excentration of the dysplastic hip can be quantified with ultrasonography. The purpose of this study was to evaluate the usefulness of ultrasound monitoring of confirmed hip dysplasia as a method for determining the appropriate time to discontinue treatment.

Material and methods: We collected a series of patients presenting unstable hips one month after birth. Ultrasonographic examinations were performed to quantify the instability. Initial treatment was forced abduction. If the infant’s weight was greater than 5.6 kg, a Pavlik harness was used. Physical examination and control ultrasound examinations were performed at 4, 8 and 12 weeks. Forced abduction and ultrasound surveillance were discontinued when the percent of acetabular cover was greater than 50%. Long-term surveillance consisted in physical examination and plain ap view of the pelvis at four months and at onset of walking.

Results: Ultrasound monitoring was instituted for 71 hips in 51 patients. Mean age at onset of the monitoring scheme was 37.7 days (range 38–74 days). Mean acetabular cover, as evaluated by ultrasound before treatment, was 35.5% (range 20–45%). After four weeks, mean cover for 42 hips was 54.7% (range 50–85%). For the other 29 hips, mean acetabular cover was 41.4% (range 36–47%) at four weeks. At eight weeks, 26 of these 29 hips had a mean cover of 60% (52–85%). Acetabular cover remained below 50% for three hips at twelve weeks. Mean HTE at four months was 20.7° (range 10–26°). At walking, all hips were centered and no irregularities were noted on the x-rays of the femoral nucleus.

Discussion: The majority of infants with unstable hips diagnosed at birth achieve spontaneous cure without treatment. For others, cure can be achieved with forced abduction but with a risk of osteochondritis. In our study, ultrasound monitoring enabled a reliable assessment of the proper moment to interrupt treatment.

Conclusion: Ultrasound examination of the hip joint is a satisfactory method for monitoring hip dysplasia in infants aged less than four months. It appears to be useful for determining the moment to interrupt treatment.