先天性胸腰段侧后凸畸形三柱截骨矫形术后冠状面失代偿

摘要

目的 探讨先天性胸腰段侧后凸畸形三柱截骨矫形术后冠状面失代偿的发生机制.方法 2008年1月至2012年6月因先天性胸腰段侧后凸畸形接受三柱截骨矫形术治疗的患者118例,男55例,女63例;年龄10～30岁,平均18岁.冠状面平衡类型:Ⅰ型(平衡状态),C7偏移小于2 cm;Ⅱ型(凸侧失平衡),C7向主弯凸侧偏移大于2 cm;Ⅲ型(凹侧失平衡),C7向主弯凹侧偏移大于2 cm.Ⅱ型和Ⅲ型为冠状面失平衡.结果 术后胸腰段侧凸和后凸均获得满意矫正.冠状面C7偏移从术前平均1.1 cm增加至术后1.5 cm.术前冠状面平衡Ⅰ型71例、Ⅱ型45例、Ⅲ型2例;术后Ⅰ型92例、Ⅱ型26例.26例(22％,26/118)有冠状面失代偿,且均为凸侧失平衡.术后Ⅱ型患者较Ⅰ型有较大的C7偏移(3.1 cm比0.2 cm)和C7偏移变化量(1.8 cm比-0.8 cm);术前Ⅱ型患者较Ⅰ型有更高的术后凸侧失平衡发生率(33％比15％).远端固定于L5及骶骨者冠状面失平衡发生率高于固定于L4及以上者(36％比14％).术后失代偿与术前C7偏移呈正相关(r=0.31,P=0.047).22例在术后1年内凸侧失代偿改善.结论 顶椎区三柱截骨矫形术可有效矫正先天性胸腰段侧后凸畸形,但术后易发冠状面失代偿.术后冠状面失代偿可能与截骨矫形和术前凸侧失平衡有关.%Objective To investigate the pathomechanism of the coronal decompensation after three-column osteotomy correction for congenital thoracolumbar kyphoscoliosis.Methods The present study reviewed 118 patients with congenital thoracolumbar kyphoscoliosis who were treated with three-column osteotomy correction between January 2008 and June 2012.There were 55 males and 63 females.Balance in the coronal plane was categorized into three types according to C7 translation (C7T,defined as the shift of the center of C7 vertebra as to the center sacral vertical line):Type Ⅰ,balanced; Type Ⅱ,coronal imbalance on the convex side (C7T≥2 cm); and TypeⅢ,coronal imbalance on the concave side (C7T≤-2 cm).Postoperative coronal decompensation was recorded if imbalance was noted on either side.Results Deformities on both coronal and sagittal planes were corrected with three-column osteotomy satisfactorily.Overall,C7T increased from 1.1 cm preoperatively to 1.5 cm postoperatively.In terms of coronal balance,there were 71 patients (60％) with Type Ⅰ,45(38％) with Type Ⅱ,and 2 (2％) with Type Ⅲ before surgery.There were 92 patients (78％) with Type Ⅰ,and 26 (22％) with Type Ⅱ after operation.Therefore,coronal decompensation occurred in 26 patients (22％),who all presented with convex imbalance.These patients had larger C7T (3.1 cm vs.0.2 cm) and changes in C7T (1.8 cm vs.-0.8 cm) than those without decompensation.Higher incidence of convex decompensation was detected in patients with preoperative Type Ⅱ balance than those with Type Ⅰ balance (33％ vs.15％,P=0.025),and also in patients with lowest instrumented vertebra at L5 or below than those at L4 or above (36％ vs.14％,P=0.004).A significant but weak correlation was found between coronal decompensation and preoperative C7T (r=0.31,P=0.047).Improvement on decompensation was observed in 22 patients within the follow-up of one year.Conclusion Postoperative coronal decompensation is a potential complication after threecolumn osteotomy correction for congenital thoracolumbar kyphoscoliosis.Its occurrence might be associated with osteotomic correction procedures and preoperative coronal imbalance on the convex side.