74 paediatric patients, 9-15 years of age, with a primary lateral patellar dislocation were randomized to either medial patellofemoral ligament repair or to nonoperative treatment with a knee brace. Both groups received physiotherapy as part of their treatment protocol. Patients were followed for 2 years for results on redislocation rate, subjective function and objective function. Redislocation rate was significantly lower in the MPFL repair group compared to the knee brace group. In contrast, subjective function in the Knee Injury and Osteoarthritis Outcome Score Child questionnaire (KOOS-Child) Sport/Play and QoL scales and objective function for Limb Symmetry Index in the single-legged hop distance test were significantly lower in the MPFL repair group compared to the knee brace group.