Prevalence of Osteochondritis Dissecans of the Capitellum in Young Baseball Players: Results Based on Ultrasonographic Findings.

BACKGROUND Osteochondritis dissecans (OCD) of the capitellum is a well-recognized cause of elbow pain and disability in adolescent athletes. However, little is known about the prevalence of OCD in adolescent baseball players. PURPOSE To determine the prevalence of OCD in baseball players aged 10 to 12 years based on ultrasonographic findings and to investigate the clinical characteristics of those with OCD lesions. STUDY DESIGN Descriptive epidemiology study. METHODS A total of 1040 players aged 10 to 12 years completed a questionnaire, ultrasound imaging, and radiographic examination to investigate OCD. Sonographic findings were classified into 5 grades (0, 1a, 1b, 2, and 3). Subjects with grade 1a, 1b, 2, or 3 were considered to have abnormal findings of the capitellum and were advised to undergo radiography. Radiographic and ultrasonographic findings were then compared. The prevalence of OCD was calculated, and differences by age and player position were determined. RESULTS Of the 1040 players, 33 (3.2%) had an abnormal finding on initial ultrasonography screening, and all 33 agreed to undergo radiography. Of them, 22 (66.7%) were found to have OCD of the capitellum on radiographs, giving an overall prevalence of 2.1%. Seven subjects (31.8%) had no history of elbow pain. Based on the radiographic classification, 20 subjects (90.9%) had stage I lesions. Analysis of OCD by age and player position revealed no significant differences. CONCLUSION The prevalence of OCD of the capitellum was 2.1% in 1000 baseball players aged 10 to 12 years, with no differences in prevalence according to age or player position.