膨胀式椎弓根螺钉在腰椎疾患中的应用

Fixation of Lumbar Instability Using Expandable Pedicle Screw:a Single Center Retrospective Review

目的探讨膨胀式椎弓根螺钉（expensive pedicle screw，EPS）在腰椎不稳症内固定治疗中的初步疗效。方法自2005年6月至2008年3月，在27例腰椎不稳症患者经椎弓根内固定手术治疗中采用EPS，其中男11例，女16例；年龄25～72岁，平均49．4岁。病程6个月～7年，平均29．4个月。患者应用EPS的合并指征依次是骨质疏松14例，对普通椎弓根螺钉固定翻修3例，术中改钉道重新植钉4例，腰骶椎锚定融合3例．增加额外的矫形力3例。采用JOA临床腰椎手术评分系统、椎体间骨性融合X线CookSD标准对疗效进行综合评定。同时观察内固定器械相关情况。结果术后1例椎间盘突出翻修病例合并脑脊液漏，经保守治疗。于术后23d切口延期愈合，未合并感染；其余患者切口均一期愈合。末见神经、脏器损伤等并发症发生。所有病例平均随访17．8个月（12～39个月）。27例患者所用EPS均完全膨胀，共81枚，每例用1～7枚不等，平均3．1枚。JOA改善率显效16例，有效7例，总有效率85．2％（23／27），其中24例达融合X线标准，融合率88．9％。1例螺钉松动、拔出，融合失败，滑脱复发；1例因术后局部不适于术后3个月取除内固定；1例固定稳定但无融合X线证据。结论本研究表明，在合并有骨质疏松等骨质条件较差的情况下，对腰椎不稳症的内固定治疗采用EPS是有效的；EPS的应用拓宽了经椎弓根内固定技术的适用范围。

Objective To evaluate the clinical and radiographic results with the use of expandable pedicle screw. Methods From June 2005 to March 2008,27 consecutive cases of thoracic or （and） lumbar diseases were included and reviewed,in which eleven were male and sixteen were female. The course of disease was six months to seven years,with a mean course of 29.4 months. Twenty seven patients received one or more expandable pedicle screws to obtain thoracolumbar stabilization. The indications for use of expandable screw are osteoporosis （14 cases）,reoperation of previous pedicle instrumentation （3 cases）,intraoperative screw relocation （4 eases）,sacral anchoring （3 cases） and construct reinforcement （3 cases）. The clinical results, radiographic fusion were evaluated based on JOA score and Cook criteria respectively. Fusion was evaluated based on anterior posterior and lateral radiographs as well as dynamic radiographs in flexion and extension. Also the complications arising from the instrumentation were recorded. Results All incisions healed by first intension except for a revision case in which the leakage of eerehrospinal fluid occurred postoperatively. With effective conservative treatments ,it finally obtained healing until 23 days after operation ,and there was no sign of infection. No complications arising from operation were found. Twenty-seven cases of pedicle screw use were available for review at a mean follow up period of 17.8 months （range,12-39 months）, A total of eighty four expandable pedicle screw were used and were shown expandable in radiograph. The effective rate of JOA was 85.2%. Twenty four of the twenty seven patients satisfied all three radiographic criteria for fusion. And the fusion rate was 88. 9%. There was one case of expandable screw loosing and pullout in a patient with recurrent spondylolisthesis. In one patient there was no radiographic evidence of fusion though no pathologic motion,and it was considered failed fusion. In anther case the pedicle screw instrumentation was removed 3 months after surgery because of local discomfort. Conclusion The resutts of this study have shown that the expandable pedicle screws can be effi- cacious in cases in which pedicle screw fixation is difficult and adds a valuable tool to the growing armamentarium of spinal instrumentation.