中文摘要：

目的：探讨下端融合椎（10west instrumented vertebra，LIV）相关影像学指标对Lenke5C型特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）患者术后冠状面平衡的影响。方法：本研究包括30例行后路选择性融合的Lenke5C型AIS患者，所有患者于术前、术后即刻及末次随访时拍摄站立前后位像及术前仰卧位拍摄左右Bending像。对术前、术后和末次随访时的冠状面平衡与uV相关影像学指标（LIV偏移、LIV旋转、LIV倾斜度、LIV尾侧椎间盘开角）进行分析。结果：所有患者平均随访33个月（24～50个月），其中LIV为L3者20例，L4者10例。30例Lenke5C型AIS患者术前冠状面胸腰弯／腰弯Cobb角平均为49-8。±5．1。，术前冠状面胸弯Cobb角平均为25．60±7．10。相关性检验发现以下3个指标与术后即刻冠状面平衡（coronaltrunkbalance，CTB）有显著相关性：（1）术前CTB（r=0．69，r2=0．48，P〈0．01）；（2）术前LIV倾斜度（r=O．63，r2=O．40，P〈0．01）；（3）术后即刻UV倾斜度（r=0．60，r2=0．36，P〈0．01）。在末次随访时，不管是术前还是术后的UV相关影像学指标均与末次随访时CTB无显著相关（P〉0．05）。结论：对行后路选择性融合术的Lenke5C型AIS患者而言，术前冠状面平衡与否及术前LIV倾斜度大小对预测术后即刻冠状面平衡有重要的作用。术前LIV倾斜大于25。的患者容易发生术后即刻冠状面失平衡。然而，LIV倾斜度对Lenke5C型AIS患者术后冠状面平衡无显著影响。

英文摘要：

Objectives： To investigate the long-term effect of radiographic parameters associated with the low- est instrumented vertebrae（LIV） on postoperative coronal trunk balance in adolescent idiopathic seoliosis（AIS） patients with type Lenke 5 curve. Methods： In this retrospective study, totally 30 AIS patients with type Lenke 5 curve who received posterior selective fusion were included. Pre- and postoperative standing upright posteroanterior and lateral radiographs as well as preoperative supine left and right side-bending radiographs were used for radiographic assessment. Bivariate correlation tests were carried on to analyze the correlation of each radiographic parameter related to the LIV and the coronal trunk balance immediately after surgery and at final follow-up. Results： The average follow-up time was 33 months（range 24-50 months）. The LIV was L3（n=20） or IA（u=10）. The average preoperative Cobb angle of the TUL curve and thoracic curve was 49.8~＋-- 5.1~ and 25.6~＋7.1~, respectively. Correlation analysis showed that the following radiographic parameters were significantly associated with the immediate postoperative coronal trunk balance（CTB）： preoperative coronal trunk balance（r=0.69, 12=0.48, P〈0.01）, preoperative LIV tih（r=0.63, 12=0.40, P〈0.01）, and postoperative LIV tilt（r= 0.60, rZ=0.36, P〈0.01）. However, at final follow-up, neither preoperative nor postoperative parameters were as- sociated with the final coronal trunk balance（P〉0.05）. Conclusions： In AIS patients with type Lenke 5 curve, preoperative coronal trunk balance and preoperative LIV tilt are very important parameters in predicting the immediate postoperative coronal trunk balance. Preoperative LIV tilt I〉25 is associated with a high risk of developing immediate postoperative coronal imbalance. During the follow-up, no radiographic parameters at either preoperation or postoperation have statistical correlation with the final coronal trunk balance.