長母趾屈筋腱皮下断裂の1例

Subcutaneous Rupture of the Flexor Hallucis Longus Tendon. Case Report

　今回，われわれは極めて稀な長母趾屈筋腱皮下断裂の症例を経験した．患者は59歳の男性，バイクツーリングから帰宅した後より右足部の違和感が出現し，右第1足趾が自動屈曲不能となった．足部に疼痛・腫脹などの異常所見は認められなかった．単純X線写真では三角骨が認められた．臨床症状より長母趾屈筋腱皮下断裂と診断し，手術を施行した．皮膚切開は足関節内側の弓状切開で行った．距骨後方には三角骨が存在し，同部位にて長母趾屈筋腱は断裂していた．断端は退縮し，端々縫合は困難であり，同側の足底筋腱を採取し腱移植し，エチボンド糸で補強した．長母趾屈筋腱は同部位では，走行が変化することや血行があまり豊富でないために断裂が生じることがある．今回の症例では，患者がバイク愛好家のため第1足趾を頻回に使用しており，これに加えて三角骨が腱に慢性的な刺激を加わえ続けたことが腱断裂の原因と考えられた．

　A unique case of complete subcutaneous rupture of the flexor hallucis longus tendon on the posteromedial aspect of the right ankle of a 59-year-old man is reported. After riding his motor-bike, the patient noticed that he was unable to move his right great toe. When there was no improvement after about a month, he came our clinic. Examination revealed the absence of pain, tenderness, and swelling. X-rays of the foot showed normal findings except for the presence of an os trigonum. A diagnosis of rupture of the flexor hallucis longus tendon was made solely on the basis of the history and physical findings. We chose to treat the patient surgically and rupture of the tendon on the posteromedial aspect of the ankle was confirmed intraoperatively. Repair was achieved with a tendon graft from the plantaris tendon of the right foot. Postoperative management consisted a short leg cast for 6 weeks and partialweight-bearing at 7 weeks. The cause of the rupture was concluded to have been riding the motor-bike and the presence of the os trigonum near the tendon.