Osteochondritis Dissecans of the Capitellum: Influence of Activity on Lesion Location Within a Zone of Propensity

Abstract

Background: There may be an association between repetitive stress on the elbow and capitellar osteochondritis dissecans (COCD). The influence of activity on the characteristics or specific location of the lesion within a capitellar zone of propensity remains unclear. Purpose/Hypothesis: The purpose of this study was to evaluate COCD in gymnasts and baseball players compared with a non–upper extremity (non-UE) sport COCD cohort. It was hypothesized that activity would influence presentation and lesion location and characteristics. Study Design: Cross-sectional study, Level of evidence, 3. Methods: Consecutive patients presenting with COCD treated in a tertiary sports medicine practice between March 2006 and March 2021 were reviewed. Demographic and imaging lesion characteristics were recorded. The sagittal inclination angle position of the lesion center relative to the humeral shaft was recorded. Intra- and interrater reliability was confirmed (intraclass correlation coefficient, 0.808; intraclass correlation coefficient, 0.824, respectively). Participants were analyzed by activity. Results: A total of 126 elbows were identified: 68 in gymnasts, 31 in baseball players, and 27 in patients with no history of UE sports. The mean age of the participants was 12.5 years (range, 8-18 years). All (100%) unilateral cases of osteochondritis dissecans (OCD) in baseball players occurred in the dominant throwing arm, compared with less hand-dominance correlation in gymnasts (64%) and non-UE athletes (67%). Significantly, 14 of the 20 (70%) patients with bilateral OCD were gymnasts ( P = .036). In non-UE athletes, lesions occurred at a mean sagittal inclination angle of 52.7° (±13.8°), with a mean lateral containment of 4.7 (±2.1) mm. In gymnasts, lesions occurred more posteriorly at 41.2° (±14.9°), with a lateral containment of 3.6 (±1.9) mm. In baseball players, COCDs occurred at 55.1° (±11.9°), with a lateral containment of 2.5 (±1.6) mm. These more posterior lesion positions in gymnasts ( P = .001) and lesser lesion containment noted in gymnasts ( P = .015) and baseball players ( P < .001) were significant. Conclusion: Compared with COCD lesions in adolescents with no history of UE sports, gymnastics participation (impact weightbearing) correlated with a higher rate of bilateral lesion formation and a more posterior (extended) lesion position. Baseball participation (resulting in valgus shear forces in the elbow) resulted in a sagittal position similar to non-UE lesions, but more lateral and with less containment.