外傷性母指伸筋腱脱臼の1例

Traumatic Dislocation of the Extensor Pollicis Tendon. Case Report

　患者は18歳の男性で，2年前バスケットボールプレー中に，ボールが右母指に当たり受傷した．その後，右母指疼痛が出現し，特に書字困難を主訴に当院初診となった．MP関節の自動屈曲時に，長母指伸筋腱が尺側に脱臼し，疼痛が生じていた．単純X線像では異常所見を認めなかった．外傷後長母指伸筋腱尺側脱臼と診断し，手術を施行した．術後9カ月の最終観察時に疼痛，脱臼を認めず，書字も可能であった．本損傷は比較的稀な外傷であるが，良好な機能的予後を獲得するためには，手術的治療が必要となることもある．

　An 18-year-old man who had injured his right thumb during a basketball game two years before began to experience pain in his right thumb, and he came to our hospital with a chief complaint of difficulty writing. Examination revealed that the extensor pollicis longus tendon became dislocated toward the ulnar side during active flexion of the metacarpophalangeal (MP) joint of the thumb and caused the pain. Plain radiography yielded normal findings. A diagnosis of posttraumatic ulnar dislocation of the extensor pollicis longus tendon was made on the basis of the history and physical findings, and surgery was performed. At the final follow-up examination 9 months post operatively, no pain or dislocation of the thumb was noted, and the patient was able to write normally. Although this was a relatively rare case, surgical intervention may be necessary to achieve a good functional outcome in such cases.