S2骶岬螺钉技术辅助增强固定在腰骶椎翻修术中的应用

S_2-Alar screw auxiliary enhancement in lumbosacral spinal revision surgery

目的探讨S_2骶岬螺钉（S_2-alar screw,S_2-AS）在腰骶椎翻修术中的效果和意义。方法 2011年6月—2014年5月,7例腰骶椎内固定失败患者在本院接受骶骨侧的S_2-AS技术增强固定。记录手术时间、出血量及相关并发症,评估腰骶椎的融合效果,并对翻修术前、术后及末次随访时的疼痛视觉模拟量表（visual analogue scale,VAS）评分和Oswestry功能障碍指数（Oswestry disability index,ODI）进行对比分析。结果所有手术顺利完成,术后随访12~36个月,平均18个月。手术时间为180~300 min,平均240 min;出血量450~800 m L,平均614 m L,未出现与S_2-AS相关的并发症。末次随访时无内固定物失败的情况出现,并达到骨性融合或可能融合标准。术前、术后及末次随访时VAS评分分别为（6.86±1.07）分、（1.85±1.10）分和（1.57±0.87）分,术前与术后相比,差异具有统计学意义（P〈0.01）;术前、术后及末次随访时ODI分别为（28.29±7.61）%、（8.57±2.64）%和（7.29±2.43）%,术前与术后相比,差异具有统计学意义（P〈0.05）;且在随访期间有进一步改善趋势。结论 S_2-AS是一种安全有效的增加骶骨侧锚定点的外科技术,能对腰骶椎翻修术时S1椎弓根螺钉固定起到辅助增强作用,从而有助于腰骶椎达到骨性融合。

Objective To explore the effect of S_2-alar screw（S_2-AS） in lumbosacral spinal revision surgery. Methods From June 2011 to May 2014,due to failed previous lumboarcal spinal surgery,7 patients accepted revision with S_2-AS to enhance the anchoring strength at sacral side. The operation time,blood loss and the complications relative to S_2-AS were recorded in the study retrospectively. The outcome of fusion at the level of L5/S1 was also evaluated. The visual analogue scale（VAS） score and Oswestry disability index（ODI） at pre-operation,post-operation and the final follow-up were recorded respectively. Results All cases were operated successfully. All cases were followed-up for 12-36 months,mean 18 months. The operation time was 180-300 min,mean 240 min. The blood loss was 450-800 m L,mean 614 m L. No complications relative to S_2-AS were found. The VAS scores at pre-operation,post-operation and the final follow-up were 6.86±1.07,1.85±1.10 and 1.57±0.87,respectively. The difference of the VAS scores between pre-revision and post-revision was statistically significant（P 0.01）. The ODI at pre-operation,post-operation and the final follow-up were（28.29±7.61）%,（8.57±2.64）% and（7.29±2.43）%,respectively. The difference of the ODI between pre-revision and post-revision was statistically significant（P 0.01）. Further improvement of ODI could be found during the follow-up. The difference of the ODI between post-revision and the final follow-up was statistically significant（P 0.05）. Conclusions The technique of S_2-AS is safe and effective in enhancing the anchoring strength at sacral side during lumbosacral fusion surgery. The anchoring force of S_2-AS can prevent the weak S1 pedicle screws from failure in the situation of lumbosacral spine revision,and it is helpful for improving the fusion of L5/S1 level.