投球動作により生じた大腿骨骨幹部骨折の1例

Femoral Shaft Stress Fracture in a Baseball Pitcher. Case Report

　投球動作により生じた大腿骨骨幹部骨折の1例を経験した．16歳，男性，野球部の投手．投球動作時に右膝関節痛を自覚するも放置していた．1カ月後に投球動作の際に右大腿部に激痛を自覚し歩行困難となった．単純X線像では右大腿骨骨幹部遠位1/3に転位のある横骨折を認めた．投球動作による疲労骨折と考え，観血的整復固定術を施行した．大腿骨骨幹部疲労骨折は長距離ランナーなどで報告があり，初発症状は膝関節痛が最も多い．スポーツ選手が動作時膝関節痛を訴えた場合，大腿骨骨幹部疲労骨折の可能性も留意する必要性があると考えられた．

　We report a case of femoral stress fracture associated with throwing action. A 16 year-old pitcher on a high school baseball team reported pain in the right knee during 1month of throwing training. He felt a “snap” in his right thigh during throwing practice and fell to the ground, unable to walk. Radiographic examination showed a displace transverse fracture of the distal third of the right femur. He underwent intramedullary stabilization of the fracture. While displaced stress fractures of femoral shaft have been reported in long-distance runners, the most common symptoms were poorly localized pain in the knee. The possibility of femoral shaft stress fractures should therefore be considered in athletes experiencing pain in the knee.