胸腰椎骨折经骨折椎体内固定术后出现钉棒断裂的原因分析及对策

目的 探讨胸腰椎骨折椎体应用椎弓根螺钉内固定术后出现钉棒断裂的原因以及预防对策。方法 对2010年3月至2013年3月应用经骨折椎体椎弓根螺钉内固定治疗的26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、是否椎管减压以及术后卧床时间对钉棒断裂者进行统计学分析。结果 发生椎弓根螺钉断裂2例，哈氏棒断裂2例。椎弓根螺钉和哈氏棒断裂平均发生时间为术后16个月。断钉断棒发生率：爆裂脱位型骨折患者(3/10)高于压缩型骨折患者(1/16)(P＜0.05)；椎板切除减压患者（2/12）高于未切除椎板患者(2/14)(P＜0.05)；术后卧床时间小于2个月患者（3/19）高于卧床2个月以上患者（1/7），此例因截瘫后一直卧床，但绝对卧床时间未超过2个月。结论 椎弓根钉棒出现断裂与手术方式选择不当、钉棒应力分布不均、脊柱后柱破坏加重、术后过早下床活动有关。严格掌握手术适应证和手术时机、同轴同平面置钉和合理预弯哈氏棒使应力均匀分布、尽量保留脊柱后柱、避免过早下床剧烈活动可有效降低钉棒断裂的发生率。

Causes of screw-rod breakage after fixation by vertebral fractures in the treatment of thoracolumbar fracture and the preventing strategies

Objective To investigate the causes of pedicle screw and harrington rod breakage after pedicle screw fixation by vertebral fractures in the treatment of thoracolumbar fracture and the preventing strategies. Methods Twenty-six patients who suffered thoracolumbar fracture and received segmental pedicle screw fixation by vertebral fractures from Mar. 2010 to Mar. 2013 were reviewed. The classification of fractures, spinal decompression and postoperative bed time were analyzed. Results Pedicle screw breakage occurred in 2 cases, and Harrington rod breakage in 2 cases. The average time of pedicle screws and Harrington rod breakage was 16 months after operation. Screw breakage rate in burst fracture dislocation patients (3/10) was higher than in compression fracture (1/16) (P<0.05), that in patients subject to laminectomy for decompression (2/12) was higher than that in those reserving the vertebral lamina (2/14) (P<0.05), and that in those with the postoperative recovery time of less than 2 mouths (3/19) was higher than that in those with the postoperative recovery time of more than 2 mouths (1/7) (this case has been bedridden after paraplegia, but absolute bed time did not exceed 2 mouths). Conclusion Pedicle screw breakage is related to the inappropriate choice of surgical approaches, the uneven stress distribution of nail bar, the spinal column damage worsened and early ambulation after operation. Strict surgical indications and timing of surgery, the same axial and plane of pedicle screw, a reasonable pre bending of Harrington rod to keep the stress distributed homogeneously, keeping the spinal column, and avoiding premature ambulation intense activity can effectively reduce the screw rod breakage.