两种不同方法置入Dynesys内固定的早期临床对比研究

Comparative study of early clinical outcomes of two different Dynesys system implantation approaches

目的比较单侧剥离半椎板切除潜行对侧扩大减压联合对侧经多裂肌间隙行Dynesys内固定与双侧剥离全椎板切除Dynesys内固定治疗退行性腰椎椎管狭窄症的早期临床效果和安全性。方法 2010年2月～2011年3月27例退行性腰椎椎狭窄患者(43个节段)行Dynesys内固定手术。15例(24个节段)行症状重侧单侧剥离半椎板切除,潜行对侧扩大减压,对侧经多裂肌间隙安装Dynesys内固定;12例(19个节段)行双侧暴露全椎板切除减压安装Dynesys内固定。通过对患者术前术后疼痛视觉模拟量表(visual analog scale,VAS)评分和腰背、下肢Oswestry功能障碍指数(Oswestry disability index,ODI),摄正侧位和动力位X线片,记录手术切口,术中术后出血量比较2种方法的临床效果和安全性。结果 27例患者得到8～20个月的随访。2组患者对比研究显示单侧剥离组的手术切口、肌肉创伤、术中出血量、术后引流量及术后初次腰痛评分改善程度优于双侧暴露安装组。影像学资料显示2组患者椎间隙前高、后高及椎间孔高度、面积均较术前明显增加。2组患者椎间隙前高、后高和椎间孔高度、面积改变量及术后节段活动度改变量差别不大。结论单侧剥离半椎板切除潜行对侧扩大减压联合对侧经多裂肌间隙行Dynesys内固定同样可以达到足够的减压效果;与双侧剥离全椎板切除减压Dynesys内固定相比,具有创伤小,术中、术后出血少,术后初次腰部疼痛评分优于后者等优点。

Objective To compare the early clinical outcomes and safety of hemilaminectomy with unilateral paravertebral dissection and laminectomy with bilateral paravertebral dissection for degenerative lumbar spinal stenosis.Methods From February 2010 to March 2011,27 patients（43 segments） with degenerative lumbar spinal stenosis were treated by Dynesys internal fixation and divided into 2 groups according to the different Dynesys implantation approaches.In unilateral group,15 patients（24 segments） were treated by hemilaminectomy with unilateral paravertebral dissection and the contralateral decompression and Dynesys pedicle screw fixation via paravertebral muscle gaps.In bilateral group,12 patients（19 segments） were decompressed by laminectomy with bilateral paravertebral dissection and Dynesys internal fixation.Visual analog scale（VAS） scores and Oswestry disability index（ODI） were evaluated,and radiograph（anterioposterior,lateral,flexion and extension） were done preoperatively and postoperatively.The length of operative incision and the intraoperative and postoperative blood loss were recorded.Results The follow-up duration ranged from 8 to 20 months for all the patients.Compared with bilateral group,there were shorter operative incision,less muscle injury,less intraoperative and postoperative blood loss,and lower postoperative VAS scores in unilateral group.Radiologic data showed that the ventro and dorso height of intervertebral space and the height and width of intervertebral foramen were significantly increased in all the patients postoperatively.But there were no significant differences in the changes of the ventro and dorso height of intervertebral space,the height and width of intervertebral foramen and range of motion between the 2 groups.Conclusion Hemilaminectomy with unilateral paravertebral dissection followed by Dynesys pedicle screw fixation can achieve the same decompression with laminectomy.However,hemilaminectomy has less operative injury,less intraoperative and postoperative blood loss,and more back pain score improvement in early postoperation by than laminectomy.