Departments of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Departments of Neurosurgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
World Neurosurg. 2021 Feb;146:e1367-e1376. doi: 10.1016/j.wneu.2020.12.017. Epub 2020 Dec 10.
The preservation of nuchal musculature is essential for preventing axial pain and cervical malalignment after laminoplasty. A few studies have examined the effect of preservation of nuchal musculature on the degenerative progression after laminoplasty. We aimed to clarify the influence of preservation of the semispinalis cervicis inserted into C2 on cervical degenerative change and alignment after laminoplasty.
We retrospectively reviewed 106 consecutive patients who underwent C3-7 laminoplasty for cervical spondylotic myelopathy during 2006-2017. Patients were classified into 2 groups according to the preservation (P-group; n = 33) or detachment (D-group; n = 73) of the Semispinalis cervicis muscles inserted into the C2 spinous process. Parameters of cervical sagittal alignment, range of motion, and progressive degenerative changes next to or within the range of laminoplasty were evaluated in cervical spine radiographs, and magnetic resonance images obtained during follow-up period.
In the D-group, the postoperative C2-7 Cobb angle significantly decreased (-0.06°/month), while the O-C2 Cobb angle significantly increased (0.07°/month). In addition, the C2-7 range of motion significantly decreased in the D-group (-0.12°/month). Degenerative changes in the laminoplasty range were found in 5 patients per group. Three patients from the D-group developed retroodontoid pseudotumors (P < 0.001).
To maintain horizontal gaze, the craniocervical segment can compensate for the loss of lordosis by increasing the Cobb angle. Excessive compensation may exert mechanical stress on the atlantoaxial junction, contributing to the development of a retroodontoid pseudotumor. Preservation of the semispinalis cervicis inserted into C2 is critical for the prevention of malalignment after laminoplasty.
保留项肌对于预防椎板成形术后的轴向疼痛和颈椎失稳至关重要。有几项研究探讨了保留项肌对椎板成形术后退行性进展的影响。我们旨在阐明 C2 棘突插入的半棘肌保留对椎板成形术后颈椎退行性改变和排列的影响。
我们回顾性分析了 2006 年至 2017 年间因颈椎病性脊髓病而行 C3-7 椎板成形术的 106 例连续患者。根据 C2 棘突插入的半棘肌（P 组，n=33）或分离（D 组，n=73）情况将患者分为两组。在颈椎侧位 X 线片和随访期间的磁共振图像上评估颈椎矢状位排列、活动范围以及椎板成形术范围内或范围内的渐进性退行性改变的参数。
在 D 组中，术后 C2-7 Cobb 角明显减小（-0.06°/月），而 O-C2 Cobb 角明显增加（0.07°/月）。此外，D 组的 C2-7 活动范围明显减小（-0.12°/月）。每组均有 5 例患者出现椎板成形术范围内的退行性改变。D 组中有 3 例患者出现齿状突后假瘤（P<0.001）。
为了保持水平凝视，颅颈段可以通过增加 Cobb 角来补偿前凸的丧失。过度补偿可能会对寰枢关节施加机械应力，导致齿状突后假瘤的发生。保留 C2 棘突插入的半棘肌对于预防椎板成形术后失稳至关重要。
