腰椎后路椎体间融合术中神经根牵拉损伤的研究

Study of nerve root traction injury in lumbar interbody fusion from posterior rout approach

[目的]探讨腰椎后路椎体间融合术中神经根牵拉损伤的发生率和神经根耐受牵拉的阈值。[方法]应用神经根安全拉钩完成腰椎后路椎体间融合手术共116例,术中应用节段性皮神经刺激体感诱发电位技术进行监测,记录SEP潜伏期和SEP波幅、神经根拉力和牵拉时间。术后10 d、1个月、3个月、1年进行随访,记录JOA评分。[结果]术中共有19例患者出现潜伏期延长、波幅下降,此时神经根拉力为(4.1±0.45)N,累积拉力为(42.89±2.96)N*min,明显高于潜伏期和波幅平稳组和好转组,术后FBSS的发生率也明显高于后两组。[结论]术中神经根的牵拉损伤是腰椎后路椎体间融合术后早期引起腰椎手术失败综合证(fail back surgery syndrome,FBSS)的主要原因,单次神经根拉力小于(4.1±0.45)N或累积拉力小于(42.89±2.96)N*min,发生神经根牵拉损伤的几率较小。

[ Objective] To discuss incidence of nerve root stretch injury and threshold value of traction injury in lumbar interbody fusion from posterior rout approach. [ Method] Totally patients were treated by lumbar interbody fusion performed with posterior approach using the safe nerve root retractor, the force of dragging nerve root and the retracting time were showed on the display device, while the latency and amplitude of the DSEP wave were measured with Keypoint to monitor the status of the neural function. JOA scores were followed up 10 days, 1 month, 3 months and 12 months after operation respectively. [Result] Nineteen cases occurred latency prolongation and wave amplitude digression during the operation, when the tensile strength to nerve root was （4. 1 ± 0. 45 ） N and accumulating strength was （42. 89 ± 2. 96） N ＊ min. The tensile force of aggravation groups exceed stable and improvement groups obviously, incidence of FBSS was higher than the other two groups. [ Conclusion ] Stretch injury of nerve root during operation is the main cause of earlier period FBSS after interbody fusion. Master single tensile force less than （4. 1 ± 0.45） N or accumulating strength less than （42. 89 ±2. 96） N ＊ min is presumed safety.