不同远端固定椎对退变性腰椎侧凸长节段后路融合疗效的影响

The effect of different distal instrumented vertebra on posterior long segment fusion for lumbar spine degenerative disease

目的：研究选择不同的远端固定椎（distal instrumented vertebra,DIV）对退变性腰椎侧凸（degenerative lumbar scoliosis,DLS）长节段后路融合（posterior spinal fusion,PSF）治疗效果的影响。方法：回顾2005年1月-2012年1月在我院诊断为DLS并行后路长节段脊柱融合手术治疗的63例患者。男性16例,女性47例,年龄50-72岁,平均61.4岁。根据术中DIV的选择不同分成两组,L5固定组（A组）：选择L5作为DIV,共44例;骶椎固定组（B组）：选择S1作为DIV,共19例。分别对两组的手术时间、出血量、固定节段数进行比较,测量并记录每例患者术前、术后末次随访的冠状面侧凸Cobb角、顶椎位移、冠状面平衡（骶骨中垂线与C7铅垂线的距离）和矢状面腰椎前凸角（T12上终板和S1上终板垂线间的夹角）、胸腰椎后凸角（T10上终板和L2下终板垂线间的夹角）、矢状面平衡（C7铅垂线与S1椎体后上缘的距离）、骨盆入射角、骨盆倾斜角和骶骨倾斜角。分析两组间的并发症发生率。结果：两组间手术时间和术中出血量无显著性差异（P〉0.05）,但A组固定节段数平均少于B组1.36个（P=0.022）;A组手术后各脊柱测量参数与术前比较均有显著性改善;B组Cobb角、顶椎位移、腰椎前凸角和胸腰椎后凸角手术前后比较有显著差异（P〈0.05）,但冠状面平衡和矢状面平衡则无显著差异（P〉0.05）;A、B两组手术前后骨盆入射角无改变（P〉0.05）;A组手术后骨盆倾斜角较术前显著减小（P〈0.05）,骶骨倾斜角则显著有增大（P〈0.05）;而B组此2项骨盆参数手术前后差异无显著性（P〉0.05）;术后矢状面失平衡、内固定松动、需翻修的L5/S1椎间盘退变、需翻修的骶骨固定等远端固定椎相关并发症A组7例（15.91%）,B组8例（42.11%）（P〈0.0001）。结论：采用后路长节段融合手术治疗退变性腰椎侧凸,DIV选择L5或S1能获得相似的矫正效果;选择L5能有效保留L5/S1的活动度;而选择S1则有较高的并发症发生率。

Objectives： To evaluate the influence of different distal instrumented vertebra（DIV） on the outcomes of posterior spinal fusion for degenerative lumbar scoliosis. Methods： 63 patients with degenerative lumbar scoliosis who underwent posterior long segment fusion surgery from January 2005 to January 2012 in our hospital were selected for the present retrospective study. There were 16 males and 47 females, and the average age was 61.4 years（range 50 to 72 years）. All patients were divided into two groups based on the different distal instrumented vertebra： L5（group A, n=44） and S1（group B, n=19）. The operation time, operative bleeding and fusion segments were compared between two groups. Radiographic measurement included coronal Cobb angle, apical vertebra translation（AVT）, coronal vertical axis（CVA）, lumbar lordosis（LL）, thoracolumbar kyphosis（TK）, sagittal vertical axis（SVA）, pelvic incidence（PI）, pelvic title（PT）, sacral slop（SS） and the amount of the fusion levels on the standing anterior-posterior radiographs before and after surgery. The complications were analyzed in the two groups. Results： Although the operation time and operative bleeding showed no significant difference between group A and B（P〉0.05）, the mean fusion segment in group A was shorter than group B（P〈0.05）. The postoperative spine parameters improved significantly in group A compared with the preoperative ones（P〈0.05）. The Cobb angle, apical vertebra translation（AVT）, lumbar lordosis（LL）, thoracolumbar kyphosis（TK） showed significant differences in group B between preoperation and postoperation（P〈0.05）. However, no difference in the coronal and sagittal balance parameters could be found（P〈0.05）. On the other hand,there was no significant difference of PI between preoperation and postoperation in group A or B（P〉0.05）. In group A, the postoperative PT significantly declined compared with the preoperative PT, and SS showed the reverse change（P〈0.05）. Meanwhile, similar change was showed in these parameters of group B, but no significant difference was noted（P〉0.05）. 7 complications were noted in group A（15.91%） and 8 in group B（42.11%）（P〈0.0001）. Conclusions： In the posterior long segment fusion for DLS, selecting L5 or S1 as distal instrumented vertebra can achieve similar outcome, while selecting L5 as DIV can effectively preserve the motion of L5/S1. Meanwhile, selecting sacral vertebra as DIV has a higher incidence of complications.