テニスによる自家筋力で発生した上腕骨内側上顆骨折の1例

Fracture of the Medial Epicondyle of the Humerus Caused by Muscle Force During a Tennis Serve. Case Report

　患者は13歳の男性で，テニスのサーブを打った瞬間に右肘に激痛が出現し，プレー続行不可能となった．単純X線像でWatson-Jones分類TypeIIの上腕骨内側上顆骨折を認め手術を施行した．自家筋力による内側上顆骨折は野球，腕相撲では比較的多くの報告があるが，テニスのサーブにおける骨折は稀な症例である．テニスのサーブは投球動作と類似しており，本骨折は投球骨折と同様のメカニズムで発症したと考えられる．

　We report the case of a 13-year-old male who experienced severe pain in his elbow after a tennis serve.　Surgery was performed, and a fracture of the medial epicondyle of the homerus (Watson-Jones classification Type II) was diagnosed.　There have been several reports of such fractures caused by muscle force during arm wrestling and in baseball players, but fractures of the humeral medial epicondyle caused by a tennis serve are rare.　The motions involving in throwing and tennis service are similar, so this fracture may have occurred by the same mechanism as fractures caused by pitching.