术中评估冠状面平衡新方法(点线法)在脊柱侧凸矫形术中的应用

The application of a new intraoperative assessment method of coronal balance in surgical treatment of scoliosis

目的介绍一种评估脊柱侧凸畸形矫形术中冠状面平衡的新方法(点线法),并探讨其在预防术后冠状面失平衡的效果.方法回顾性收集2016年1月至2016年12月46例脊柱侧凸患者的病历资料,男19例,女27例;年龄7~76岁,平均(28.24±21.16)岁.均接受后路矫形手术,下固定椎位于L3及其以下.术中均应用点线法进行冠状面序列评估,即在基本矫形完成后通过判断上固定椎椎体中心是否位于通过耻骨联合中心点与下固定椎中心点的测量杆,以此评估冠状面矫形效果.记录术前、术后即刻及末次随访时主弯Cobb角、冠状面平衡距离(coronal balance distance,CBD)、Oswestry功能障碍指数(Oswestry disability index,ODI)、疼痛视觉模拟评分(visual analogue scale,VAS)及脊柱侧凸研究学会-22简明量表调查问卷(Scoliosis Research Society questionnaires-22,SRS-22).根据术CBD及C7铅垂线与主弯的位置关系,将患者术前冠状面序列分为三型,并进行亚组分析.结果46例患者中术前冠状面失平衡发生率为47.82%(22/46),B型为10例,C型为12例;术后即刻冠状面失平衡发生率为17.39%(8/46);末次随访时发生率为10.87%(5/46).术前主弯Cobb角平均为57.24°±26.51°,术后即刻矫正至14.71°±10.17°,与术前的差异有统计学意义(t=13.211,P=0.000),矫正率平均为73.53%±1.88%.术前CBD平均为(22.54±13.97)mm,术后即刻为(15.49±10.27)mm,较术前明显改善(t=3.665,P=0.001),矫正率平均为25.58%±52.39%.46例患者末次随访时VAS评分(t=21.529,P=0.000)、OD(I t=44.434,P=0.000)及SRS-22评分(t=24.023,P=0.000)均较术前明显改善.亚组分析显示,B型组患者术后即刻主弯Cobb角矫正率为70.34%±6.02%,与术前的差异有统计学意义(t=5.437,P=0.000),CBD矫正率为37.45%±29.03%,与术前的差异有统计学意义(t=2.607,P=0.028);而C型组患者术后即刻主弯Cobb角矫正率为72.92%±3.67%(t=7.319,P=0.000),CBD矫正率为44.79%±5.63%(t=7.545,P=0.000),均较术前明显改善.结论点线法是一种简单、有效的术中冠状面平衡评估方法,能够辅助外科医生在畸形矫形术中客观地评估冠状面恢复程度,及时调整冠状面矫形程度,以减少术后冠状面失平衡的发生.

Objective To introduce a new method for assessing coronal balance in surgical treatment of scoliosis,and to explore its effectiveness in preventing postoperative coronal imbalance.Methods The data of forty-six consecutive patients,who underwent posterior surgery for spine deformity correction from January 2016 to December 2016,were retrospectively analyzed.The series included 19 males and 27 females with an average age of 28.24±21.16 years(7-76 years),and with lower instrumented vertebra(LIV)located at the level of L3 or below.Point-line method was used to evaluate coronal balance by determining whether the center of upper instrumented vertebra was located at the measuring rod passing through the centers of symphysis pubis and LIV among all patients during surgery.Preoperative,postoperative 1 week and 3 months Cobb angle,coronal balance distance(CBD),Oswestry Disability Index(ODI),Visual Analogue Scale(VAS),and Scoliosis Research Society Questionnaires-22(SRS-22)were measured and recorded,and statistical analysis was conducted.And then,subgroup analysis was performed according to preoperative coronal imbalance classification to further evaluate the effectiveness of the new method.Results Among 46 patients in this study,the prevalence of preoperative coronal imbalance was 47.82%(22/46).Of them,ten patients were type B coronal im-balance and eleven patients were type C coronal imbalance.The prevalence of coronal imbalance at one week after operation was 17.39%(8/46),and the prevalence of coronal imbalance at final follow-up was 10.87%(5/46).The results showed that the mean main Cobb angle was 57.24°±26.51°and 14.71°±10.17°at pre-operation and immediate post-operation,respectively.The differ-ence was statistically significant compared to preoperative value(t=13.211,P=0.000),and the average improvement rate was 73.53%±1.88%.Preoperative coronal balance distance CBD ranged from 2.76 mm to 66.73 mm,with an average of 22.54±13.97 mm;the mean CBD was 16.00±14.85 mm at immediate post-operation.The difference was statistically significant(t=3.665,P=0.001),with an average correction rate of 25.58%±52.39%.Our clinical outcome analysis showed that among 46 patients,the pre-operative VAS was 8.11±0.89,and the final follow-up VAS was 4.15±0.79.There was a significant difference between pre-opera-tion and the last follow-up(t=21.529,P=0.000).The preoperative ODI score was 49.76±5.84,and the final follow-up ODI score was 25.74±3.92.The difference was statistically significant(t=44.434,P=0.000).The preoperative SRS-22 was 10.57±2.13,and the final follow-up SRS-22 was 21.89±2.35.Compared to pre-operation,the difference was statistically significant(t=24.023,P=0.000).The subgroup analysis showed that in patients with type B coronal imbalance,the mean Cobb angle correction rate was 70.34%±6.02%at immediate post-operation,and there was a significant difference compared to pre-operation(t=5.437,P=0.000);the average CBD correction rate was 37.45%±29.03%,and significant difference was found(t=2.607,P=0.028).In type C patients,the average Cobb angle and CBD correction rate at immediate post-operation was 72.92%±3.67%and 44.79%±5.63%,respective-ly,and significant difference was found(t=7.319,P=0.000;t=7.545,P=0.000).Conclusion Point-line method was a simple and effective technique for intraoperative assessment of coronal balance,which could assist surgeons to objectively evaluate the result of restoration of the coronal alignment.The use of point-line method is contributed to improve clinical outcomes of spinal deformity correction surgery,and to prevent the occurrence of postoperative coronal imbalance.