Asif Hamza, Tohidi Mina, Hopman Wilma, Yen David
Department of Surgery, Queen's University, Kingston, ON, Canada.
School of Medicine, Queen's University, Kingston, ON, Canada.
J Spine Surg. 2021 Sep;7(3):376-384. doi: 10.21037/jss-21-41.
The primary purpose of this study was to determine the association between pre-operative cervical sagittal alignment and the extent of cord decompression in the form of increased spinal cord width and cerebrospinal fluid (CSF) space in front of and behind the cord in patients undergoing laminectomy for cervical spondylotic myelopathy (CSM). Secondary objectives included an assessment of the correlation between increasing numbers of levels decompressed and the post-operative cervical spine sagittal alignment, the effect of laminectomy on the change in alignment, as well as effect of laminectomy on pre-existing spinal cord signal abnormality.
This retrospective cohort study included patients who underwent cervical laminectomies, without fusion, between 2015 and 2020. Chart review was used to collect baseline variables. Cervical sagittal alignment, width of the spinal cord, and the CSF space in-front and behind the cord was measured pre-operatively and post-operatively using magnetic resonance imaging (MRI) scans for each patient. The correlation between change in measured parameters and pre-operative cervical sagittal alignment was assessed using Spearman's correlation.
Thirty-five patients were included. Average age was 65.29±10.98 years old. The majority of patients (80%) underwent laminectomies at 3-4 levels. Average pre-operative sagittal alignment determined by the Cobb angle was 6.05°±14.17°, while the average post-operative Cobb angle was 3.15°±16.64°. The change in Cobb angle was not statistically significant (P=0.998). Eleven patients (32%) had pre-operative kyphotic sagittal alignment. The average time from surgery to post-operative MRI scan was 20.44±13.18 months (range, 3-39; median, 18.5; IQR, 23.5). There was no statistically significant association between increasing levels of decompression and change in alignment (P=0.546). Cord signal abnormality persisted after decompression. There was a moderate correlation between lordotic pre-operative cervical sagittal alignment and change in space in-front of the cord (correlation coefficient 0.337, P=0.048) and change in cord width (correlation coefficient 0.388, P=0.021).
Severity of pre-operative kyphotic sagittal alignment is associated with decreased spinal cord drift and extent of decompression. The pre-operative sagittal alignment is not significantly associated with the change in post-operative alignment. Increasing number of levels decompressed does not worsen a kyphotic cervical spine sagittal alignment.
本研究的主要目的是确定在因脊髓型颈椎病（CSM）接受椎板切除术的患者中，术前颈椎矢状位排列与脊髓减压程度之间的关联，脊髓减压程度以脊髓宽度增加以及脊髓前后脑脊液（CSF）间隙增宽的形式体现。次要目标包括评估减压节段数量增加与术后颈椎矢状位排列之间的相关性、椎板切除术对排列变化的影响，以及椎板切除术对术前已存在的脊髓信号异常的影响。
这项回顾性队列研究纳入了2015年至2020年间接受非融合颈椎椎板切除术的患者。通过查阅病历收集基线变量。使用磁共振成像（MRI）扫描对每位患者术前和术后的颈椎矢状位排列、脊髓宽度以及脊髓前后的脑脊液间隙进行测量。使用Spearman相关性分析评估测量参数变化与术前颈椎矢状位排列之间的相关性。
共纳入35例患者。平均年龄为65.29±10.98岁。大多数患者（80%）接受了3 - 4节段的椎板切除术。通过Cobb角确定的术前矢状位排列平均为6.05°±14.17°，而术后Cobb角平均为3.15°±16.64°。Cobb角的变化无统计学意义（P = 0.998）。11例患者（32%）术前矢状位为后凸。从手术到术后MRI扫描的平均时间为20.44±13.18个月（范围3 - 39个月；中位数18.5个月；四分位间距23.5个月）。减压节段增加与排列变化之间无统计学意义的关联（P = 0.546）。减压后脊髓信号异常持续存在。术前颈椎矢状位前凸与脊髓前方间隙变化（相关系数0.337，P = 0.048）以及脊髓宽度变化（相关系数0.388，P = 0.021）之间存在中度相关性。
术前矢状位后凸的严重程度与脊髓漂移减少及减压程度相关。术前矢状位排列与术后排列变化无显著关联。减压节段数量增加不会使颈椎矢状位后凸排列恶化。
