BACKGROUND: Consequences of osteochondral fractures associated with patellar dislocation can be severe for younger patients. Precise 3-dimensional characterization of fracture location, size, frequency, and radiographic associations remain undefined in this population. PURPOSE: (1) To define the topographic characteristics of osteochondral fractures in pediatric and adolescent patients with first-time patellar dislocations and (2) to determine the relationship between these characteristics and radiographic and patient factors. STUDY DESIGN: Cross-sectional study
Level of evidence, 3. METHODS: A retrospective observational study was conducted between 2015 and 2023 of consecutive patients aged <
18 years undergoing surgical intervention for displaced osteochondral fractures in the setting of first-time patellar dislocation. Three-dimensional location and relative injury frequency were quantified with heat map analysis. Subgroup analysis of intraoperative osteochondral fracture size and location was conducted using chi-square testing and an independent RESULTS: The study cohort included 82 knees (80 patients) with first-time patellar dislocation and osteochondral fracture. A total of 97 osteochondral fractures were identified, with the lateral femur as the most common fracture site at 55% (n = 53), as compared with 43% (n = 42) for the patella and 2% (n = 2) for the lateral trochlea. Patellar osteochondral fractures were significantly larger than femoral lesions (mean ± SD, 258 ± 168 mm CONCLUSION: We found that the most common site for osteochondral fracture was the femur, although patellar osteochondral fractures were significantly larger. Factors that affect anatomic structure and ligamentous laxity appear to contribute to patterns of osteochondral fractures.