Recurrent Patellar Dislocation in Adolescents

Background: The clinical outcome of arthroscopic medial retinaculum plication (MRP) compared with vastus medialis plasty (VMP) for recurrent patellar dislocation in adolescents is unknown.Hypothesis: Arthroscopic MRP can yield similar results to open VMP for recurrent patellar dislocation in adolescents.Study Design: Randomized controlled clinical trial; Level of evidence, 2.Methods: Sixty adolescent patients were randomly divided into 2 groups to receive arthroscopic MRP and open VMP respectively. The patients were followed up at 3, 6, 12, and 24 months postoperatively and computed tomography (CT) scans were taken immediately after operation and at 12 and 24 months postoperatively to evaluate the position of the patella. Knee function was evaluated at 24 months postoperatively according to the International Knee Documentation Committee (IKDC), Kujala, Lysholm, and Tegner rating scales. For those who underwent operation more than 3 years previously, an additional review was taken to evaluate the latest patellar stability status.Results: The final follow-up time was 56.8 ± 21.5 months (range, 24-92 months) and 59.1 ± 24.7 months (range, 24-88 months), respectively, in the MRP and VMP groups. The CT examination showed that the correction of the patellar position deteriorated over time in both groups. The final patellar position was significantly better than that before surgery in the VMP group, but not in the MRP group. The VMP group had significantly better clinical results at each follow-up compared with the MRP group. The IKDC, Lysholm, Kujala, and Tegner scores were 62.5 ± 6.2, 70.7 ± 5.1, 76.6 ± 4.8, and 3.9 ± 0.7, respectively, in the MRP group, and 71.8 ± 7.1 ( P < .001), 79.4 ± 5.5 ( P < .001), 82.9 ± 4.8 ( P < .001), and 5.1 ± 1.4 ( P < .001), respectively, in the VMP group at the 2-year follow-up. Five patients (17.9%) in the MRP group and 2 patients (7.7%) in the VMP group ( P = .267) experienced episodes of redislocation at the final follow-up.Conclusion: Arthroscopic MRP is less reliable for maintaining the corrected position of the patella and for functional recovery compared with VMP for recurrent patellar dislocation in adolescents.