高度椎体圧潰を呈した胸腰椎破裂骨折に対する後方short segment pedicle screw法―前方再建術併用に関する検討

Surgical Outcomes of Posterior Short Segment Pedicle Screw Fixation with or without Anterior Reconstruction for Severely Comminuted Thoracolumbar Burst Fractures

　椎体圧潰率50％以上の高度圧潰を呈する胸腰椎破裂骨折に対して，後方short segment pedicle screwのみで対応した後方法群19例と，これに前方再建術を併用した前後合併法群27例を対象として，手術高位矢状面アライメントを中心に術後成績を比較検討した．観察時の局所後弯角および矯正損失は前後合併法群1.3°，5.4°，後方法群7.7°，10.4°であり，後方法群では術直後の矯正は比較的良好であっても経過中に後弯変形が出現していた．後方法群では観察時局所後弯角5°未満の非後弯群7例と5°以上の後弯群12例に分かれたが，良好な椎体高復元と3椎間固定が後弯変形防止に関与している可能性が示唆された．

　The surgical outcomes of patients treated for severely comminuted thoracolumbar burst fractures by posterior short-segment pedicle screw (PSSPS) fixation with or without anterior reconstruction were retrospectively reviewed.　At the final follow-up examination the local kyphosis angle (LKA) of 1.3° and correction loss of 5.4° in the group of 27 patients treated by anterior reconstruction combined with PSSPS were significantly (p ＜ 0.01) smaller than the 7.7° and 10.4°, respectively, in the group of 19 patients that underwent PSSPS alone.　In the group treated by PSSPS alone, 7 patients had an LKA of ＜ 5° (non-kyphosis group), and 12 patients had an LKA of ≧ 5° (kyphosis group).　During the follow-up period anterior body collapse, vertebral kyphosis, and LKA were greater in the kyphosis group than in the non-kyphosis group, and the differences were significant (all p ＜ 0.05).　The mean number of fused segments in the non-kyphosis group, 2.4, was significantly greater than the mean of 2.0 in the kyphosis group (p ＜ 0.05).　Treatment by PSSPS alone could not prevent recurrent kyphosis.　Surgical restoration of the height of the fractured vertebral bodies and the number of fused segments may be associated with recurrent kyphosis after treatment by PSSPS alone.