Prevalence and Clinical Significance of Osseous Abnormalities Around the Medial Epicondyle According to Physeal Status in Young Athletes.

BACKGROUND

Medial epicondylar apophyseal fragmentation is a radiographic finding frequently observed in young athletes; however, its clinical significance remains unclear, particularly in relation to skeletal maturity and mechanical loading.

PURPOSE: To investigate the prevalence of medial epicondylar apophyseal fragmentation according to physeal status and throwing versus nonthrowing elbow, and to clarify its clinical significance in young athletes.

METHODS

This retrospective observational study included 506 elbows from athletes aged 19 years or younger presenting with elbow pain. Radiographic evaluation was performed using standardized plain radiographs. Osseous abnormalities around the medial epicondyle were assessed and classified according to physeal status (open vs. closed). The prevalence of abnormalities was compared using the χ 2 test. Associations with throwing status were also evaluated.

RESULTS

Osseous abnormalities were identified in 186 of 323 elbows (57.6%) with an open physis and in 19 of 183 elbows (10.4%) with a closed physis ( P <0.001). When stratified by throwing status, abnormalities were observed in 204 of 409 throwing elbows (49.9%) compared with 1 of 97 nonthrowing elbows (1.0%) ( P <0.001). No osseous abnormalities were identified in nondominant elbows in any of the patients.

CONCLUSIONS

Medial epicondylar apophyseal fragmentation is frequently observed during skeletal immaturity and decreases after physeal closure. The strong association with throwing activity may reflect a load-dependent radiographic finding. These findings indicate that apophyseal fragmentation may represent a stress-related radiographic finding rather than a persistent pathologic condition requiring immediate intervention.

CLINICAL RELEVANCE: Medial epicondylar apophyseal fragmentation is a common finding in skeletally immature symptomatic throwing athletes and may be interpreted as a growth-related phenomenon, highlighting the importance of avoiding misinterpretation as a pathologic lesion.