後方矯正固定術後に重度の冠状面off balanceを生じた成人期特発性側弯症の1例

Severe Coronal Imbalance after Posterior Correction and Fusion Surgery for Adult Idiopathic Scoliosis. Case Report

　患者は44歳の女性で，ダブルカーブの成人期特発性側弯症に対し，後方矯正固定術を施行した．術後次第に冠状面のoff balanceが進行し，46歳時に歩行障害が出現した．初回手術時の胸椎カーブの矯正が腰椎カーブより不良であったこと，可動椎間でのバランスの代償が生じなかったことがoff balanceの原因と考えられた．再手術では，腰椎カーブのCobb角が増加する方向に骨切りし，歩行障害は改善した．成人期特発性側弯症に対する後方矯正固定術では，冠状面バランスの調整に留意する必要があると考えられた．

　A 44-year-old woman underwent posterior correction and fusion surgery for double major-curve-type adult idiopathic scoliosis.　After surgery, the patient complained of deteriorating coronal imbalance, and it ultimately resulted in a gait disturbance two years postoperatively.　The reasons for the severe coronal imbalance were poorer correction of the thoracic curve than of the lumbar curve, and the rigidity of the L5-S1 segment which could not compensate for the imbalance.　Salvage surgery was performed to restore coronal balance by increasing the Cobb angle of the lumbar curve.　After surgery, coronal balance improved, and the patient was able to walk without a cane.　Control of coronal balance may be an important factor in correction and fusion surgery for adult idiopathic scoliosis.