胸腰椎Chance型骨折（屈曲伸延損傷）の治療成績

Clinical Results of the Chance Type Fractures at the Thoracolumbar Spine

　胸腰椎Chance型骨折の治療成績について検討した．症例は男5例，女2例の7例であった．損傷部位は全例胸腰椎移行部で，損傷型はpure bone type，combined typeがそれぞれ2例ずつ，burst typeが3例であった．Pure bone typeの2例は保存的に加療し，他の5例は椎弓根螺子を用いて後方固定した．受傷後平均2年9カ月時点で全例骨癒合した．平均後弯角は21°から17°へ，椎体変形は68％から75％へ改善した．Burst typeも含め後方固定の有用性が示された．

　We reviewed Chance type fractures of the thoracolumbar spine in five males and two females treated at our institution.　The levels of injury ranged from T10 to L2, and the classification was the pure bone type in two patients, the combined type in two patients, and the burst type in three patients.　The two patients with the pure bone type were managed conservatively, and the other five patients were treated by posterior fusion with pedicle screw fixation.　At a mean follow-up period of 33 months, bone union had been achieved in all seven patients.　The average kyphotic angle improved from 21°(3～34°) to 17°(5～35°), and the percent wedging deformity of the vertebral body improved from 68% (50～100%) to 75% (60～100%).　These results suggested that posterior spinal fusion with pedicle screws is useful for the treatment of chance type factures of the thoracolumbar spine, including burst-type fractures.