病的骨折を伴う大腿骨頚部骨囊腫治療後の大腿骨頭壊死に対し大腿骨転子間弯曲内反骨切り術を行った1例

Curved Intertrochanteric Varus Osteotomy for Avascular Necrosis of the Femoral Head after Surgery for a Pathologic Femoral Neck Fracture through a Solitary Bone Cyst of the Femoral Neck. Case Report

　病的骨折を伴う大腿骨頚部骨囊腫治療後の大腿骨頭壊死症に対し大腿骨転子間弯曲内反骨切り術を行った1例を経験したので報告する．症例は16歳の女性で，右大腿骨頚部骨囊腫に合併した，転位型大腿骨頚部病的骨折の診断であった．病巣掻爬，6.5mm cannulated screwと3.0mm Kirschner鋼線による骨接合，血管柄付き腸骨移植術を行った．骨癒合は得られたが，大腿骨頭壊死症（Type C-1，Stage 2）となり，大腿骨転子間弯曲内反骨切り術を行った．骨切り部は35°内反矯正し，つば付きCHSで固定した．術後3年6カ月の単純X線像では，関節裂隙は保たれており，関節症性変化は認めなかった．JOAスコアは88点と良好な関節機能を保っている．

　We report the case of a 16-year-old woman in whom curved intertrochanteric varus osteotomy was performed for osteonecrosis of the femoral head after treatment of a solitary bone cyst complicated by a pathological displaced fracture of the femoral neck. The patient was diagnosed with a displaced pathological fracture of the femoral neck through a solitary bone cyst and treated by curettage and internal fixation combined with a vascularized iliac bone graft. Six months postoperatively a diagnosis of osteonecrosis of the femoral head (type C-1, stage 2) was made based on the radiographic and MRI findings. Curved intertrochanteric varus osteotomy was performed, and an compression hip screw was used for rigid fixation after the osteotomy. A varus angulation of 35°was obtained, and good clinical and radiographic results were observed 42 months postoperatively.