Medial Patellofemoral Ligament Reconstruction vs Nonoperative Treatment for Recurrent Lateral Patellar Dislocation: Three-Year Results From a Randomized Controlled Trial

Background: Medial patellofemoral ligament reconstruction (MPFL-R) is the primary surgical intervention for recurrent lateral patellar dislocation (LPD). Isolated MPFL-R is recommended for patients without anatomic high-risk factors that predispose to further dislocations. Purpose: To compare instability recurrence in patients with recurrent LPD without underlying anatomic risk factors treated with MPFL-R versus active rehabilitation. Study Design: Randomized controlled clinical trial; Level of evidence, 1. Methods: Patients aged 12 to 30 years with recurrent LPD and no underlying anatomic high-risk factors for further dislocations—specifically, no severe trochlear dysplasia (Dejour D) and a tibial tuberosity–trochlear groove distance ≤20 mm on computed tomography—were randomized to receive knee arthroscopy with isolated MPFL-R followed by active rehabilitation (MPFL group) or knee arthroscopy without reconstruction followed by active rehabilitation (control group). The primary outcome was subjective persistent patellar instability at 3 years. Knee function at baseline and 1 and 3 years was assessed by the following patient-reported outcome measure (PROM) scores: Knee injury and Osteoarthritis Outcome Score (KOOS), Kujala Knee Score, Cincinnati Knee Rating System, and Noyes Sports Activity Rating Scale. Results: Between 2010 and 2019, 61 patients (72.1% female) were included in the study and randomized, with 30 assigned to the MPFL group and 31 to the control group. At 3-year follow-up, subjective persistent patellar instability was reported by 5 patients in the MPFL group (16.7%) versus 15 patients in the control group (53.6%), corresponding to an odds ratio of 5.8 (95% CI, 1.7-19.4; P = .003). Both groups reported significant improvements in all PROM scores from baseline to 3 years. However, no significant differences in PROM scores were observed between the groups at any follow-up time point. Conclusion: Isolated MPFL-R was more effective than active rehabilitation alone in preventing patellar instability after 3 years. Trial Registration: ClinicalTrials.org (NCT02263807).