Impact of the COVID-19 Pandemic on Prevalence of Capitellar Osteochondritis Dissecans in Preadolescent Baseball Players in Japan

Background: Capitellar osteochondritis dissecans (OCD) is considered to have a multifactorial cause, including repetitive microtrauma and other intrinsic factors. The COVID-19 pandemic in 2020 markedly restricted baseball-related physical activity in preadolescent baseball players, providing an opportunity to examine whether this restriction affected the prevalence of capitellar OCD. Purpose: To compare the prevalence of capitellar OCD among preadolescent baseball players before, during, and after the COVID-19 pandemic. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The authors retrospectively analyzed data for 5006 preadolescent baseball players aged 9 to 12 years who had undergone elbow screening in Tokushima, Japan, before (2018-2019), during (2020-2021), and after (2023-2024) the COVID-19 pandemic. Screening consisted of questionnaires, physical examinations, and ultrasonographic evaluation of the throwing elbow. Players with abnormal ultrasonographic findings underwent radiography and, when necessary, magnetic resonance imaging. Results: The authors examined 1935 preadolescent baseball players before the COVID-19 pandemic (prepandemic group), 1671 during the pandemic (pandemic group), and 1400 after the pandemic (postpandemic group). There were no statistically significant differences between the groups in characteristics, including school grade, school grade at the time of starting baseball, baseball experience, and playing position. There was also no significant difference in the prevalence of capitellar OCD among the prepandemic, pandemic, and postpandemic groups (1.9% [36/1935], 1.3% [21/1671], and 1.4% [19/1400], respectively; P = .283). All measures of elbow pain and physical examination findings were lower during the pandemic period than during the prepandemic period, and most increased again during the postpandemic period. Conclusion: The prevalence of capitellar OCD in preadolescent baseball players did not significantly decrease during the COVID-19 pandemic, despite temporal changes in the prevalence of elbow pain and positive findings on physical examination.