The 3-in-1 procedure for recurrent dislocation of the patella in skeletally immature children and adolescents

BACKGROUND: Recurrent patellar dislocations are common injuries in children and adolescents. The subjective and functional results of soft tissue surgical management in a population that was skeletally immature at the time of surgery have not been reported. HYPOTHESIS: The 3-in-1 procedure is an effective treatment for recurrent patellar dislocation in skeletally immature patients. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-five skeletally immature patients (age at operation, 13.5 +/- 3.8 years) who were practicing sports and suffering from recurrent unilateral patellar dislocation were included in the study and followed until skeletal maturation. Clinical evaluation included the modified Cincinnati rating system and the Kujala score, anthropometry, plain radiography, and isokinetic dynamometry. RESULTS: The average follow-up was 3.8 years (range, 2.5-6 years). The mean modified Cincinnati score increased from 51.7 +/- 12.6 preoperatively to 94.3 +/- 10.8 (P < .02), while the mean Kujala scores increased from 52.4 +/- 12.7 preoperatively to 93.8 +/- 14.2 (P < .02). The Insall-Salvati index remained essentially unchanged, being 1.04 +/- 0.2 preoperatively and 1.02 +/- 0.3 at latest follow-up. Significant differences were found between the operated and the contralateral limb in the various isokinetic strength variables at all angular velocities measured at the latest follow-up (.05 < P < .0042). CONCLUSION: The 3-in-1 procedure is a safe, reliable management option for recurrent patellar dislocation in skeletally immature patients. Side-to-side differences in isokinetic strength and in anthropometric indices persist despite subjective success of the procedure.