颈前路内固定融合治疗外伤性下颈椎损伤术后邻近节段矢状面角度丢失的相关因素分析

Risk factors of the occurrence of adjacent segment angular loss after anterior cervical fusion in patients with cervical injury

目的 :探讨外伤性下颈椎行颈前路融合内固定(anterior cervical fusion,ACF)术后邻近节段矢状面角度丢失的相关因素。方法:回顾性分析396例行ACF治疗的下颈椎外伤患者,记录患者年龄、性别、随访时间、手术方式、入院及末次随访ASIA评分(ASIA分级A^E级分别记为1~5分),在颈椎侧位X线上测量上区域角、下区域角、局部后凸角、融合节段角度、邻近椎体及椎间隙角度等相关参数,回顾所有患者术前MRI、CT,明确邻近节段损伤情况,所有患者局部后凸角术后角度丢失大于5°归为A组(术后邻近节段角度丢失组,23例),术后邻近节段角度无丢失为B组(373例),并通过T检验、χ2检验、Fisher确切概率法对以上相关因素行两组间对比分析,采用Logistic回归分析ACF术后邻近节段角度丢失发生的危险因素。分析邻近节段椎间隙、椎体及融合节段角度在局部后凸角、上区域角、下区域角中所占比例,明确ACF术后邻近节段角度丢失的主要部位。结果:ACF术后邻近节段角度丢失发生率为5.81%(23/396),A、B组年龄分别为48.26±8.61岁、31.04±6.17岁,入院时ASIA评分两组分别为3.5±0.8、3.7±1.0,差异均有显著性(P=0.021,P=0.045)。手术方式、性别、随访时间、末次随访ASIA评分在A组和B组间差异无显著性(P>0.05)。两组患者术前CT、MRI上显示非手术节段MRI椎间盘信号异常(A组3/23,B组13/373)、不伴椎间韧带复合体损伤的单侧非移位型关节突骨折(A组2/23,B组0/373)有显著性差异(P<0.001,P=0.003)。多变量回归分析显示年龄、MRI上非手术节段椎间盘信号异常、不伴椎间韧带复合体损伤的单侧非移位型关节突骨折是ACF术后邻近节段矢状面角度丢失的危险因素(P分别为0.031、0.006、0.002),入院时ASIA评分与ACF术后邻近节段后凸畸形发生无相关性(P=0.301)。上邻近第1椎间隙角度丢失在局部后凸角、上区域角、下区域角角度丢失中分别为78.07%、85.00%、90.19%,上邻近第1椎间隙角度丢失是邻近节段角度丢失的主要成分。结论:ACF术后局部角度丢失有一定发生率,年龄、MRI上非手术节段椎间盘信号异常及不伴椎间韧带复合体损伤的单侧非移位型关节突骨折是ACF术后后凸畸形发生的危险因素,以上邻近节段角度丢失为主。

Objectives： To investigate risk factors of adjacent segment angular loss after anterior cervical fusion（ACF） in patients with cervical injury. Methods： A retrospective analysis was carried out, 396 patients undergoing ACF were included in the study. Factors such as age, gender, follow-up time, operation methods,ASIA scores（grade A-E recorded as 1-5 score respectively） in admission and at final follow-up were recorded. Radiographic parameters such as kyphosis, fusion segment angle, adjacent vertebral angle, adjacent intervertebral angle were measured, adjacent segment injury was identified by using MRI and CT. Patients were divided into two groups based on the angle loss at adjacent segment for 5°. 23 cases were in angular loss group（group A） and 373 in non angular loss group（group B）. The comparative results between the two groups were analyzed by T-test, Chi-square test or Fisher exact probability. Risk factors of adjacent segment angle loss after ACF were analyzed by using multivariate logistic regression. To identify the majority of the angle loss of adjacent segment after ACF, the proportion of the adjacent intervertebral angle, the vertebral angle and the fusion segment angle in the local kyphosis, the upper region angle and the lower region angle were analyzed. Results： The occurrence of adjacent segment angular loss after ACF was 5.81%（23/396）. Age was 48.26±8.61 and 31.04±6.17 years（P=0.021） in group A and B, ASIA in admission for group A and B was 3.5 ±0.8 and 3.7 ±1.0（P =0.045）. Follow-up time, operation method, gender and ASIA at final follow-up showed no significant differences between group A and B（P〉0.05）. Significant difference was noted with respect to adjacent segment injury including abnormal disc signals in non-operation segment on MRI, unilateral,undisplaced cervical facet joint fracture without disc-ligament complex injury appeared in group A compared with group B（P〈0.001 and P =0.003, respectively）. Age, abnormal disc signals in non-operation segment on MRI, unilateral, undisplaced facet fracture without disc-ligament complex injury were independent risk factors of this complication by using multivariate logistic regression（P=0.031, 0.006, 0.002, respectively）. By analyzing radiographic parameters, the angular loss of upper adjacent intervertebral space in the local kyphosis, the caudal angle and the distal angle was 78.07%, 85.00% and 90.19%, respectively. The angular lose in upper adjacent disc resulted in a progressive angular lose of adjacent segment. Conclusions： The incidence of adjacent segment angle loss after ACF is correlated to age, abnormal disc signals of non-operation segment on MRI, unilateral, undisplaced facet joint fracture without disc-ligament complex injury is considerable, mainly in the upper adjacent segment.