中文摘要：

目的评估经椎弓根椎体截骨术（pedicle subtraction osteotomy，PSO）截骨椎邻近椎间盘水平前纵韧带骨化对强直性脊柱炎（ankylosing spondylitis，AS）伴胸腰椎后凸畸形矫正的影响。方法回顾性分析2007年9月至2015年8月102例行胸腰椎单节段PSO截骨矫形的AS后凸患者资料，男92例，女10例，年龄1-65岁，平均（35．6±11．8）岁。根据PSO截骨椎邻近椎间盘前纵韧带骨化与否分为骨化组54例和非骨化组48例，并比较分析两组间单节段PSO截骨矫形角度以及椎体和椎间盘对后凸矫正的贡献是否存在差异，以及两组间远期脊柱骨盆矢状面形态的矫形丢失是否存在差异。结果骨化组单节段PSO截骨矫形角度36．3°±6．9°显著小于非骨化组41．5°±6．9°，差异有统计学意义。椎间盘楔形变对截骨角度的贡献在非骨化组中显著大于骨化组（22．9％vs．7．8％，P〈0．001）。统计比较骨化组及非骨化组随访〉2年以上的脊柱矢状面参数显示矢状面平衡，（1．7±4．5）cmvs．（-0．2±4．0）cm，差异有统计学意义；骨盆倾斜角，3．5°±8．2°vs．2．0°±10．4°，差异有统计学意义；腰椎前凸角，-7．9°±11．9°vs．-0．1°±11．9°，差异有统计学意义；骶骨倾斜角，4．5°±9．3°vs．1．6°±7．9°，差异有统计学意义。这些指标的矫正丢失在非骨化组明显较大。非骨化组的椎间盘楔形变的矫正丢失也稍大，但差异无统计学意义（-2．10±6．20vs．-0．10±3．70，P=0．09）。骨性截骨角随访则在两组间均无显著矫正丢失。结论对AS伴胸腰段后凸患者行PSO截骨矫形时选择邻近节段椎间盘前纵韧带未骨化的椎体作为截骨椎可获得相对更多的单节段后凸矫形效果，但远期随访时其发生矫正丢失的概率更大。

英文摘要：

Objective To investigate anterior longitudinal ligaments （ALL） ossified surrounding osteotomy vertebra im- pact the lordosing effect of pedicle subtraction osteotomy （PSO） in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis （AS）. Methods We retrospectively reviewed 102 AS patients with thoracolumbar kyphosis treated with single-level PSO at our institution from September 2007 to August 2015. There were 92 male and 10 female. The average age was （35.6±11.8） years old （range from 17 to 65 years old）. Patients were stratified into ossified group （54 cases） and non-ossified group （48 cases） based on the presence of ALL ossification adjacent to osteotomy vertebra. Compared the contribution of adjacent disc wedging to total correction of each PSO segment between the ossified and non-ossified groups. The long-term correction loss of spine and pelvic sagittal morphology were also evaluated and compared between the 2 groups. Results Patients in the ossified group accomplished significantly lower amount of correction in single level segment of PSO （36.30±6.9° vs. 41.5°±6.9°）, and there was significant difference between the two groups. The contribution of adjacent disc wedging to total correction of PSO was significantly larg- er in the non-ossified group （22.9% vs. 7.8%, P〈0.001）. For subgroups with a minimum 2 year follow-up, loss of corrections con- cerned sagittal vertical axis （SVA）, which was （1.7±4.5） cm vs. （-0.2±4.0） cm in ossified group and non-ossified group, and there was significant difference between the two groups. Pelvic tilt （PT） was 3.50±8.2° vs. 2.0°±10.4°, lumbar lordosis （LL） was -7.9°± 11.9° vs. -0.1 °± 11.9° and sacral slope （SS） was 4.5°±9.3° vs. 1.6°±7.9°, and there were all significant differences between the two groups. The change of adjacent disc wedging angle was marginally higher in the unossified group （-2.1°±6.2° vs. -0.1°±3.7°, P= 0.09）, but there was no significant diffe