脛骨顆間隆起骨折の線維性癒合後7年経過後の再骨折

Refracture 7 Years after the Fibrous Union of a Tibial Intercondylar Eminence Fracture

　陳旧性脛骨顆間隆起骨折では，膝伸展時の疼痛や膝関節の前方動揺性や伸展力の減少を来すことが多い．本症例は小児期に脛骨顆間隆起骨折を受傷し，線維性に癒合後，無症状に経過して，7年後にスポーツ活動で再骨折を来した．骨接合術時の問題点は，骨片が巨大化しており，解剖学的整復が困難なことと，骨片の転位による前十字靱帯(ACL)の短縮であった．術後伸展制限が残存したが，抜釘と顆間窩形成術により改善した．本症例のように骨片の巨大化，ACL短縮を伴う場合には，骨接合時に一期的な顆間窩形成術が必要である．

　The clinical manifestations of ununited avulsion fractures of the intercondylar eminence of the tibia include pain on knee extension, a low level of abnormal anterior instability, and slight loss of extension.　Our patient sustained a fracture of the tibial intercondylar eminence in childhood, and conservative treatment resulted in strong fibrous union.　The patient had no particular problems engaging in a range of sports activities.　Reports of refracture following fibrous union have been rare.　Osteosynthesis was performed to treat the recurrent fracture in our patient because the anterior cruciate ligament was found to be normal.　The problems in the treatment are enlargement of the fragment, difficulty in anatomically reducing the fragment, and shortening of the anterior cruciate ligament.　Femoral notchplasty plus osteosynthesis is neccessary to avoid an extension problem.