腰椎短节段椎弓根螺钉固定术后近端邻近节段前凸原因分析

Pathogenesis analysis of proximal junctional lordosis after short-level posterior pedicle screw fixation in lumbar spine

目的分析腰椎后路椎弓根螺钉固定术后近端邻近节段前凸的可能原因，探讨合理的应对措施。方法回顾分析2001年12月至2005年8月345例进行腰椎后路椎弓根螺钉患者，根据Oswestry功能障碍指数评价患者的临床效果，影像学检查观察近端邻近节段前凸情况，测量邻近节段椎间角、腰前凸角、腰骶角，并分析年龄、融合节段范围、腰骶力线对近端邻近节段前凸形成的影响。结果全部患者随访2～6年（平均3．8年），术后Oswestry功能障碍指数为9．7～46．2（平均19．6±10．7）。78例（22．6％）术后出现近端邻近节段前凸，37例（10．7％）出现临床症状，21例（6．1％）接受再次手术。年龄大于60岁、术后腰前凸减小、垂直骶骨的患者近端椎间角前凸发生率较高，而与固定节段数目无明显关系。结论腰椎短节段后路固定对恢复生理曲度无明显作用，年龄大于60岁、腰前凸减小、骶骨垂直可能是近端邻近节段前凸的危险因素。

Objective To analyze the possible reasons for proximal junctional lordosis（PJL） after short-segment posterior pedicle screw fixation in lumbar spine and discuss its proper management. Methods From December 2001 to August 2005, 345 patients were treated by short-segment pedicle screw fixation and these patients were reviewed. Clinical outcome was evaluated according to Oswestry Disability Index （ODI）. Proximal junctional lordosis was assessed evaluated on radiographs, by measuring lumbar lordosis angle, segmental angle at proximal level and lumbar-sacral angle. Risk factors of proximal junctional lordosis were analyzed. Results All patients were followed-up for 2 to 6 years （ average 3. 8 years）. ODI after lumbar surgery was 9.7-46. 2（ average 19. 6± 10. 7 ）. PJL was noted in 78 patients （ 22. 6% ）, 37 （ 10. 7% ） of whom were symptomatic and 21 （6. 1% ） received revision surgery. PJL was more commonly occurred in patients over 60 years old, with reduced lumbar lordosis or vertical sacrum. The number of fusion-segment was not correlated to the occurrence of PJL. Conclusions Short-segment posterior pedicle screw fixation can not improve lumbar sagittal alignment. Age over of 60 years, reduced lumbar lordosis and vertical sacrum are possible risk factors of PJL sacrum.