AAOS2013：矢状平衡纠正对颈椎序列的影响评估

引言：安全有效的截骨矫形方法可恢复脊柱的矢状平衡，有助于成人脊柱畸形重建手术。但关于这些截骨术对颈椎的效果尚未被关注，本研究拟讨论经椎弓根截骨（pedicle subraction osteotomy,PSO）和椎体切除（vertebral column resection, VCR）手术对颈椎序列的影响。
方法：评估169例患者的脊柱全长影像学资料，其中70例（平均年龄59岁）脊柱矢状平衡异常超过10cm者进行了PSO（58例）或VCR（13例），另外99例矢状平衡正常，即C7垂线<5cm。测量术前、术后颈椎和腰椎前凸、C2和T1倾斜、C7垂线与骨盆的对线关系等情况，同时测量始于齿状突尖端的垂线与L5-S1间盘后部的水平距离。
结果：平均随访517天，腰椎前凸的平均改变为19.25度（p<0.001）。矢状平衡矫正后C7垂线(mean Δ -47mm, p<0.001)、齿状突-L5/S1垂线(mean Δ -54mm, p<0.001)和骶骨角(mean 4°, p=0.020)的变化有统计学意义，颈椎曲度、C2及T1倾斜情况无显著变化。
讨论和结论：与预料相符，本研究表明PSO和VCR手术对C7垂线的变化有显著作用，这种水平方向的变化可以通过齿状突垂线的变化表现出头部相对骨盆位置的改善，但不能通过C2或T1倾斜或颈椎曲度的变化来体现。PSO和VCR可以改变齿状突垂线，意味着头部以骨盆为参照更靠近最佳位置，但不意味着整个颈椎序列的改善。颈椎前凸也许在很大程度上与T1倾斜角相关（参照腰椎前凸与骨盆投射角），我们认为对上胸椎的处理可能有助于纠正颈椎序列。
与颈椎相关的拓展阅读：

• Spine：颈椎术后并发症的危险因素分析
• 颈椎手术费用增加或与老龄化有关
• J Neurosurg Spine:CT测量证实颈椎侧块螺钉技术可用于大部分儿童患者
• 中国康复医学会颈椎病专业委员会眩晕研究学组成立
• 王岩：固定还是置换——颈椎手术方式的思考
• JNS:一种双切口颈椎前路多节段椎间融合固定技术
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The Effect of Sagittal Plane Correction on Cervical Spine Alignment 
INTRODUCTION
The surgical management of fixed sagittal imbalance in the adult spinal deformity patient has benefitted from the development of safe and effective osteotomies to restore normal sagittal alignment1-4. Little focus, however,
has been placed on the effect of these osteotomies on cervical spine alignment. This study was performed to investigate the changes that occur in the cervical spine after pedicle subtraction osteotomy (PSO) or vertebral column resection (VCR).
METHODS
Full length radiographs on 169 patients were reviewed. Seventy patients (mean age 59 years) undergoing either PSO (n=58) or VCR (n=13) with sagittal plane imbalance of >10 cm were compared with 99 patients with normal sagittal balance as defined by a c7 plumbline of <5cm. Pre- and post-operative cervical and lumbar lordosis, C2 and T1 tilt, C7 plumb line and pelvic alignment were measured. In addition, we measured the horizontal distance from a plumb line originating at the tip of the odontoid to the posterior aspect of the L5-S1 disc.
RESULTS
At average follow-up of 517 days, the average change in lumbar lordosis was 19.25° (p<0.001). Statistically significant changes were observed in the C7 plumb line (mean Δ -47mm, p<0.001) odontoid-L5/S1 plumb line (mean Δ -54mm, p<0.001) and in sacral slope (mean 4°, p=0.020) after sagittal correction. No significant change was seen in overall cervical lordosis or in C2 or T1 tilt.
DISCUSSION AND CONCLUSIONS
This study showed significant and expected restoration of the C7 plumb line after undergoing PSO or VCR. This correction of translational deformity was accompanied by a significant improvement in the position of the head over the pelvis when measured by the odontoid plumb line but did not result in a change in angular alignment measured by C2 or T1 tilt or overall cervical lordosis. Correction of a translational deformity with PSO or VCR resulted in a significant change in the odontoid plumb line, suggesting the head was moved closer to the ideal position over the pelvis. This was not accompanied by a change in overall angular alignment of the cervical spine. As cervical lordosis is to a large extent dependent on T1 tilt (analogous to lumbar lordosis and pelvic incidence), we hypothesize that control of the upper thoracic spine may be necessary if correction of cervical angular alignment is desired.