JSES - 2026-04-09 - Journal Article
Influence of Repetitive Batting on Capitellar Subchondral Bone Density Distribution.
Matsui Y, Momma D, Ike S, Numaguchi K, Kondo E, Iwasaki N
Topics
Key Takeaway
Throwing exposure increased capitellar subchondral bone density (mean HU 962 vs 884, p=0.044) in collegiate baseball players, but batting handedness produced no detectable side-specific capitellar loading difference.
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Summary
This cross-sectional CT-OAM study asked whether repetitive batting independently contributes to capitellar subchondral bone loading in collegiate baseball players by comparing four elbow groups stratified by throwing and batting handedness. Throwing elbows demonstrated significantly higher mean HU and %HDA than non-throwing elbows across all comparisons. Batting handedness conferred no additional side-specific capitellar density difference, implicating throwing—not batting—as the dominant mechanical driver of capitellar loading.
Key Limitation
All subjects were collegiate-level right-handed throwers with no symptomatic OCD, limiting generalizability to younger adolescent players in whom OCD most commonly develops and in whom bone is more susceptible to repetitive loading.
Original Abstract
BACKGROUND
Osteochondritis dissecans of the capitellum occurs in adolescent baseball players, with repetitive throwing recognized as a major risk factor. Whether repetitive batting contributes to cumulative capitellar loading remains unclear. We hypothesized that repetitive batting would increase cumulative mechanical loading on the humeral capitellum, as assessed with computed tomography osteoabsorptiometry (CT-OAM).
METHODS
In this cross-sectional study, 32 healthy male collegiate baseball players (64 elbows), all right-handed throwers, underwent bilateral elbow CT during the off-season. Based on batting handedness and throwing side, elbows were categorized into four groups (T&B, Contralateral, T, B). Capitellar subchondral bone density was analyzed with CT-OAM. Mean Hounsfield unit (HU) values and percentage of high-density area (%HDA, top one-third of HU values) were compared between groups.
RESULTS
Throwing elbows showed higher mean HU and %HDA than non-throwing elbows. The T&B group had greater values than the Contralateral group (mean HU, 935 ± 153 vs 913 ± 88.9, P = .046; %HDA, 32.6 ± 14.8 vs 25.0 ± 15.5, P = .049). Similarly, the T group had greater values than the B group (mean HU, 962 ± 101 vs 884 ± 142, P = .044; %HDA, 31.8 ± 14.5 vs 26.4 ± 12.5, P = .042). Batting handedness was not associated with side-specific difference (T&B vs T and Contralateral vs B).
CONCLUSION
Throwing exposure was associated with greater capitellar subchondral bone density, whereas no clear batting-related side-specific difference was detected in collegiate players.