胸腰椎骨折内固定术后椎弓根螺钉断裂的原因分析及对策

目的：探讨胸腰椎骨折内固定术后椎弓根螺钉断裂的原因以及预防措施。方法：对2000年6月至2006年9月应用椎弓根螺钉内固定系统治疗的273例资料完整的胸腰椎骨折病例进行回顾性分析,按照骨折类型、植骨融合方式、是否使用横杆以及内固定取出时间对椎弓根螺钉断裂者进行统计学分析。结果：发生椎弓根螺钉断裂22例，椎弓根螺钉断裂平均发生时间为术后19．9个月，大多（19／22）在取内固定物前复查X线片时发现。断钉发生率：爆裂型骨折患者（13／76）显著高于压缩型骨折（6／132）和骨折脱位型患者（3／65）（P〈0．01）；椎间植骨组（1／25）和后外侧植骨组（7／110）显著低于未植骨组（7／70）（P〈O．05）；未使用横杆组（8／49）显著高于使用横杆组（14／224）（P〈O．05）；术后12个月以上取出内固定组（9／97）高于6～12个月取出内固定组（6／169）（P〈O．05）。结论：椎弓根螺钉断裂可能与手术方式选择不当、植骨融合不当、未正确使用横连杆、内置物取出过迟有关。严格掌握手术适应证和手术时机、有效植骨融合、合理使用横杆以及及时取出内固定可有效防止椎弓根螺钉断裂发生。

The causes of pedicle screw breakage after thoracolumbar fracture surgery and the preventing strategies

Objective:To investigate the causes of pedicle screw breakage after thoracolumbar fracture surgery and the preventing strategies.Method:237 patients who suffered thoracolumbar fracture and received segmental pedicle screw fixation from June 2000 to September 2006 were reviewed.Analyzing was performed according the classification of fracture,bone graft,usage of corsslink and the time of implant removal.Result:Pedicle screw breakage happened in 22 cases.The average time of the pedicle screw breakage was 19.9 months.Most of the breakages(19/22) were found with radiograph before the operation of instrument removal.Pedicle screw breakage rate in burst fracture group was significantly higher than that in compressive fracture or dislocated fracture group(P<0.01).Screw breakage rate in interbody fusion group and posterolateral fusion group were all significantly lower than that in non-fusion group(P<0.05).Screw breakage rate in crosslink group was lower than that of without crosslink group(P<0.05).Screw breakage rate in delayed implant removal group was higher than that of timely instrument removal group(P<0.05).Conclusions:Correct surgical decision making,successful fusion of bone graft,usage of crosslink and timely removal of the implant will be helpful to prevent the pedicle screws from being broken.