后路腰椎椎间融合术对邻近节段退变的影响

Influence of posterior lumbar interbody fusion to adjacent segment degeneration

目的腰椎融合术改变了腰椎的生物力学环境,使邻近节段应力集中,本研究就后路腰椎椎间融合术(pos-terior lumbar interbody fusion,PLIF)对邻近节段退变(adjacent segment degeneration,ASD)的影响进行探讨。方法 2002～2006年,采用PLIF治疗腰椎退行性疾病患者60例,其中男38例,女22例;年龄为25～77岁,平均46岁。观察其术后ASD的发生率、发生部位及影像学特点,对是否"悬浮固定"及内固定融合范围引发ASD的风险进行对比。结果所有患者随访2.0～6.5年,平均4.5年。影像学有退变表现者11例(18.3%),其中9例发生在内固定头侧邻近节段,2例发生在尾侧邻近节段。是否进行"悬浮固定"对ASD的影响无统计学意义,多节段融合与单节段融合对ASD的影响也无统计学意义。结论腰椎融合手术引起邻近节段的应力异常集中,增加了ASD发生率,头侧邻近节段较尾侧节段更容易发生退变。

Objective Lumbar interbody fusion induces the change of lumbar normal biomechanical environment.The adjacent segments have the character of stress concentration.This study aimed to observe the lumbar adjacent segment degeneration（ASD） after posterior lumbar interbody fusion（PLIF）.Methods From 2002 to 2006,60 patients（38 males and 22 females,aged 25-77 years old,with a mean value of 46 years old） with symptomatic degenerative diseases underwent PLIF.The incidence of ASD,position and radiographic characteristics were studied.The relation between ＂floating fusion＂ and ASD were compared,and the relation of fusion range and ASD was also studied.Results All patients were followed up for 2.0-6.5 years（mean 4.5 years）.Eleven patients（18.3%） were found to have radiographic characteristics of ASD.Nine of them had ASD at cranial segments,the other 2 at caudal segments.The difference between using ＂floating fusion＂ or not in the risk of ASD was not statistically significant.The difference between single-level fusion and double-level fusion was not statisticaly significant,either.Conclusion After PLIF,stress concentration of adjacent segments was abnormal,which increases the incidence of ASD.The cranial segment has a higher degeneration risk than the caudal segment.