Abstract
Objective To characterize medial patellofemoral ligament (MPFL) lesions and osteochondral lesions after a first episode of lateral patellar dislocation (LPD) in young patients.
Methods We evaluated 91 magnetic resonance imaging scans from patients under 18 years of age (average age: 14.5 years), with a first episode of LPD, from a single pediatric emergency center, between 2008 and 2012. The location and extension of the MPFL lesions and the location and size of the osteochondral lesions were analyzed.
Results We found MPFL injuries in 49.5% (45) of the cases. Total and partial ruptures of the MPFL were found in 10.9% (10) and 39.5% (36) of the patients respectively. Among the total ruptures, 70% (7) occurred in the patellar insertion, 20% (2), in the femoral insertion, and 10% (1) were multifocal. Of the partial injuries, 72% (26) were patellar, 19.4% (7), femoral, and 8.3% (3), multifocal. Osteochondral lesions were found in 38% (35) of the patients; 62.8% (22) were located in the patella, and 34.2% (12), in the lateral femoral condyle, while only 3% (1) were multifocal.
Conclusion Half of the cases presented MPFL injuries. Partial MPFL injuries at the patellar attachment are the most common pattern in skeletally-immature patients suffering an LPD for the first time. More than one third of the cases of first-time LPD in children will present a concomitant osteochondral injury, mostly at the patella.
Level of Evidence Level III.
adolescents
Keywords
lateral patellar dislocation - medial patellofemoral ligament - osteochondral injury - children - adolescents
