Congenital dislocation of the patella. Part II: orthopaedic management.

Five patients (eight knees) with diagnosed congenital dislocation of the patella and well-documented charts were reviewed. Age at diagnosis ranged from 4 days to 6 years. A flexion contracture of the knee and femorotibial rotatory dislocation of varying degrees were present in all the cases. The quadriceps was active in all the cases, producing knee flexion in four cases. Foot deformity was associated in all the cases (clubfoot, calcaneovalgus, or congenital vertical talus). Gradual correction of knee flexion contracture with serial casting was attempted in five cases leading to an almost complete extension in two cases. Treatment of patellar dislocation was surgical in all the cases, consisting in extensive quadriceps release (seven knees) or V-Y lengthening (one knee), division of lateral soft tissues, and reefing of the medial retinaculum and capsule. Intraoperative anomalies were recorded. At an average follow-up of 6.9 years, all the patients are able to walk on their operated limb, and the patella is centered in the trochlea in all the cases. Knee mobility, rotatory dislocation, and daily function were improved in seven cases.