Cleveland Clinic Foundation, Center for Spine Health, Cleveland, Ohio 44195, USA.
J Neurosurg Spine. 2009 Dec;11(6):667-72. doi: 10.3171/2009.7.SPINE08656.
Analysis of cervical sagittal deformity in patients with cervical spondylotic myelopathy (CSM) requires a thorough clinical and radiographic evaluation to select the most appropriate surgical approach. Angular radiographic measurements, which are commonly used to define sagittal deformity, may not be the most appropriate to use for surgical planning. The authors present a simple straight-line method to measure effective spinal canal lordosis and analyze its reliability. Furthermore, comparisons of this measurement to traditional angular measurements of sagittal cervical alignment are made in regards to surgical planning in patients with CSM.
Twenty preoperative lateral cervical digital radiographs of patients with CSM were analyzed by 3 independent observers on 3 separate occasions using a software measurement program. Sagittal measurements included C2-7 angles utilizing the Cobb and posterior tangent methods, as well as a straight-line method to measure effective spinal canal lordosis from the dorsal-caudal aspect of the C2-7 vertebral bodies. Analysis of variance for repeated measures or Cohen 3-way (kappa) correlation coefficient analysis was performed as appropriate to calculate the intra- and interobserver reliability for each parameter. Discrepancies in angular and effective lordosis measurements were analyzed.
Intra- and interobserver reliability was excellent (intraclass coefficient > 0.75, kappa > 0.90) utilizing all 3 techniques. Four discrepancies between angular and effective lordotic measurements occurred in which images with a lordotic angular measurement did not have lordosis within the ventral spinal canal. These discrepancies were caused by either spondylolisthesis or dorsally projecting osteophytes in all cases.
Although they are reliable, traditional methods used to make angular measurements of sagittal cervical spine alignment do not take into account ventral obstructions to the spinal cord. The effective lordosis measurement method provides a simple and reliable means of determining clinically significant lordosis because it accounts for both overall alignment of the cervical spine as well as impinging structures ventral to the spinal cord. This method should be considered for use in the treatment of patients with CSM.
分析患有颈椎病（CSM）的患者的颈椎矢状畸形需要进行全面的临床和影像学评估，以选择最合适的手术入路。通常用于定义矢状畸形的角度影像学测量值可能并不适合用于手术计划。作者提出了一种简单的直线方法来测量有效的椎管前凸，并分析其可靠性。此外，还比较了这种测量方法与 CSM 患者手术计划中矢状颈椎排列的传统角度测量方法。
使用软件测量程序，由 3 名独立观察者在 3 次不同的时间对 20 例 CSM 患者的术前颈椎侧位数字 X 线片进行了分析。矢状测量包括使用 Cobb 和后切线方法测量 C2-7 角，以及从 C2-7 椎体的背侧到尾侧测量有效椎管前凸的直线方法。使用方差分析或 Cohen 3 路（kappa）相关系数分析，根据需要计算每个参数的组内和组间可靠性。分析了角度和有效前凸测量之间的差异。
使用所有 3 种技术，组内和组间可靠性均很好（组内系数>0.75，kappa>0.90）。在 4 个角度和有效前凸测量值存在差异的病例中，有前凸角度测量值的图像在椎管前侧并没有前凸。所有这些差异都是由于在所有情况下脊柱滑脱或背侧突出的骨赘导致的。
尽管角度测量方法可靠，但用于测量矢状颈椎排列的传统方法并未考虑到脊髓的前侧障碍物。有效的前凸测量方法提供了一种简单可靠的确定临床上显著前凸的方法，因为它既考虑了颈椎的整体排列，也考虑了脊髓前侧的压迫结构。在治疗 CSM 患者时应考虑使用这种方法。
