Thirty-Six Months of Experience and 30° of Hip Internal Rotation as Critical Thresholds for Capitellar Osteochondritis Dissecans in Youth Baseball Players

BACKGROUND: Capitellar osteochondritis dissecans (OCD) is a serious throwing injury that can lead to long-term elbow dysfunction. While a longer duration of competitive play is a suspected risk factor, no specific cutoff value has been established to identify players at high risk. PURPOSE: To identify independent risk factors for capitellar OCD and determine the optimal cutoff value for the duration of competitive play in youth baseball players. METHODS: This cross-sectional study analyzed 853 youth baseball players (aged 9-12 years) who participated in medical check-ups. OCD was diagnosed using ultrasonography and confirmed by radiography. Eight candidate variables (weight, Rohrer index, baseball experience, history of pain, and internal rotation [IR] of the bilateral shoulders and hips) were analyzed. Independent risk factors were identified using multivariable logistic regression, with variable selection performed using a penalized regression approach and model validation based on the corrected Akaike information criterion. Optimal cutoff values were determined using receiver operating characteristic (ROC) curve analysis. RESULTS: The prevalence of OCD was 2.81% (24/853). Multivariable analysis identified three independent risk factors: longer baseball experience (p = 0.004), a history of shoulder or elbow pain (p = 0.035), and decreased internal rotation of the nondominant hip (p = 0.002). ROC curve analysis yielded an optimal cutoff value of 36 months for baseball experience (AUC = 0.704; sensitivity = 0.875; specificity = 0.508). For the nondominant hip, an internal rotation cutoff value of 30° was identified (AUC = 0.715; sensitivity = 0.625; specificity = 0.749). CONCLUSION: Baseball experience of 36 months or longer and nondominant hip internal rotation of less than 30° are significantly associated with OCD. These objective cutpoints may enhance the efficiency of medical screenings by identifying higher-risk players who need further evaluation. Given the cross-sectional design of this study, additional prospective research is needed to determine whether modifying these risk factors can reduce OCD incidence. LEVEL OF EVIDENCE: Level III; Cross-Sectional Case-Control Design; Prognosis Study.