损伤单元矢状位非稳定区对称椎弓根系统内固定结合植骨融合术治疗胸腰椎骨折

To fix the unstable region of sagittal injured unit symmetrically with pedicle screws combined with bone graft fusion for treating thoracolumbar fractures

目的探讨损伤单元矢状位非稳定区对称椎弓根系统内固定结合植骨融合术治疗胸腰椎骨折的安全性与有效性。方法选取2011年11月—2015年11月收治的单节段胸腰椎骨折患者65例,其中男41例,女24例;年龄23～60岁,平均36.7岁。骨折部位:T_7 1例,T_9 2例,T_(10) 4例,T_(11) 8例,T_(12) 14例,L_1 19例,L_2 13例,L_3 3例,L_4 1例。AO分型:A型34例,B型27例,C型4例。美国脊柱损伤协会(ASIA)分级为A级1例,B级2例,C级6例,D级15例,E级41例。胸腰椎损伤分类及损伤程度评分(TLICS):4分9例,5分29例,6～8分23例,9～10分4例。受伤至手术时间2～12 d,平均5.3 d。定义伤椎连同上、下间隙及其所对应的后方结构作为1个损伤单元,将此损伤单元在矢状位上分为3区:Ⅰ区,椎体上1/3、上位关节突关节、上位椎间隙及其对应的后方韧带复合体;Ⅱ区,椎体中1/3、椎弓根、椎板、棘突及棘上韧带;Ⅲ区,椎体下1/3、下位关节突关节、下位椎间隙及其对应的后方韧带复合体。非稳定区为损伤单元中主要受累区域。以非稳定区为中心上下对称植入椎弓根螺钉固定,结合植骨融合进行治疗。观察患者术前、术后即刻及末次随访时神经功能恢复情况、伤椎前缘高度比、矢状面Cobb角恢复情况。结果 65例患者均顺利完成手术,术中发现脑脊液漏3例,予以相应处理后痊愈。所有患者均获随访,随访时间12～24个月,平均17.3个月。无内固定物松动、移位及断钉、断棒等并发症发生。植骨均达到骨性愈合,愈合时间10～13个月,平均11.4个月。末次随访时神经功能ASIA分级为A级1例、B级1例、C级3例、D级9例、E级51例,较术前显著改善(Z=–2.963,P=0.014)。术前、术后即刻及末次随访时伤椎前缘高度比分别为53.2%±6.8%、91.3%±8.3%、89.5%±6.6%,矢状面Cobb角分别为(16.3±8.1)、(2.6±7.5)、(3.2±6.8)°。术后即刻及末次随访时伤椎前缘高度比及矢状面Cobb角均较术前显著改善,差异有统计学意义(P<0.05);术后即刻及末次随访间比较差异无统计学意义(P>0.05)。结论依据损伤单元分区理论设计椎弓根植钉原则,实施非稳定区对称椎弓根系统内固定植骨融合术治疗胸腰椎骨折安全、可靠,临床效果满意。

Objective To discuss the security and effectiveness of fixing the unstable region of sagittal injured unit symmetrically with pedicle screws combined with bone graft fusion for treating thoracolumbar fractures.Methods A series of 65 patients with a single level thoracolumbar fracture between November 2011 and November 2015 were included in the study. There were 41 males and 24 females with an average age of 36.7 years（range, 23-60 years）. The fracture segments included T_7 1 case, T_9 in 2 cases, T_（10） in 4 cases, T_（11） in 8 cases, T_（12） in 14 cases, L_1 in 19 cases,L_2 in 13 cases, L_3 in 3 cases, and L_4 in 1 case. According to AO classification, there were 34 cases classified as type A,27 cases type B, and 4 cases type C. The neurological function was evaluated by American Spinal Injury Association（ASIA） grade score, there were 1 case at grade A, 2 cases grade B, 6 cases grade C, 15 cases grade D, and 41 cases grade E.The thoracolumbar injury severity score（TLICS） was 4 in 9 cases, 5 in 29 cases, 6-8 in 23 cases, 9-10 in 4 cases. The time form injury to operation was 2-12 days（mean, 5.3 days）. The fractured vertebra, along with the superior and inferior discs were defined as a injured unit and divided into three parts on the sagittal position： region Ⅰ mainly including the superior disc, cephalic 1/3 of injured vertebra, and posterior ligamentous complex as to oppose; region Ⅱ mainly including the middle 1/3 of injured vertebra, pedicles, lamina, spinous process, and supraspinal ligament; region Ⅲ mainly including the inferior disc, caudal 1/3 of injured vertebra, and posterior ligamentous complex as to oppose. The unstable region was defined as the key injured region of the vertebra. Pedicle screws were fixed symmetrically and correspondingly with bone grafting to treat thoracolumbar fractures. The neurological status, ratio of anterior body height, and sagittal Cobb angle were collected at preoperation, immediate after operation, and last follow-up to evaluate surgical and clinical outcomes.Results All patients accepted operation safely and were followed up 12-24 months（mean, 17.3 months）. Cerebrospinal fluid leakage occurred in 3 patients, and cured by symptomatic treatment. There was no complications such as loosening,displacement, and breakage of internal fixator. Bony fusion was achieved in all patients at 10-13 months（mean,11.4 months） after operation. At last follow-up, according to ASIA grading, 1 case was grade A, 1 grade B, 3 grade C,9 grade D, and 51 grade E, showing significant difference when compared with preoperative data（Z=–2.963, P=0.014）.The ratio of anterior body height at preoperation, immediate after operation, and last follow-up were 53.2%±6.8%,91.3%±8.3%, 89.5%±6.6% respectively; and the sagittal Cobb angle were（16.3±8.1）,（2.6±7.5）,（3.2±6.8）° respectively. The ratio of anterior body height and the sagittal Cobb angle at immediate after operation and at last follow-up were significantly improved when compared with preoperative values（P〈0.05）, but no significant difference was found between at immediate after operation and at last follow-up（P〉0.05）. Conclusion It is safe and reliable to treat thoracolumbar fractures under the principle of fixing the unstable region of injured unit symmetrically with pedicle screws combined with bone grafting.