Nagamoto Yukitaka, Iwasaki Motoki, Sugiura Tsuyoshi, Fujimori Takahito, Matsuo Yohei, Kashii Masafumi, Sakaura Hironobu, Ishii Takahiro, Murase Tsuyoshi, Yoshikawa Hideki, Sugamoto Kazuomi
Department of Orthopaedics, Osaka University Graduate School of Medicine, Suita, Osaka;
J Neurosurg Spine. 2014 Sep;21(3):417-24. doi: 10.3171/2014.5.SPINE13702. Epub 2014 Jun 13.
Cervical laminoplasty is an effective procedure for decompressing the spinal cord at multiple levels, but restriction of neck motion is one of the well-known complications of the procedure. Although many authors have reported on cervical range of motion (ROM) after laminoplasty, they have focused mainly on 2D flexion and extension on lateral radiographs, not on 3D motion (including coupled motion) nor on precise intervertebral motion. The purpose of this study was to clarify the 3D kinematic changes in the cervical spine after laminoplasty performed to treat cervical spondylotic myelopathy.
Eleven consecutive patients (6 men and 5 women, mean age 68.1 years, age range 57-79 years) with cervical spondylotic myelopathy who had undergone laminoplasty were included in the study. All patients underwent 3D CT of the cervical spine in 5 positions (neutral, 45° head rotation left and right, maximum head flexion, and maximum head extension) using supporting devices. The scans were performed preoperatively and at 6 months after laminoplasty. Segmental ROM from Oc-C1 to C7-T1 was calculated both in flexion-extension and in rotation, using a voxel-based registration method.
Mean C2-7 flexion-extension ROM, equivalent to cervical ROM in all previous studies, was 45.5° ± 7.1° preoperatively and 35.5° ± 8.2° postoperatively, which was a statistically significant 33% decrease. However, mean Oc-T1 flexion-extension ROM, which represented total cervical ROM, was 71.5° ± 8.3° preoperatively and 66.5° ± 8.3° postoperatively, an insignificant 7.0% decrease. In focusing on each motion segment, the authors observed a statistically significant 22.6% decrease in mean segmental ROM at the operated levels during flexion-extension and a statistically insignificant 10.2% decrease during rotation. The most significant decrease was observed at C2-3. Segmental ROM at C2-3 decreased 24.2% during flexion-extension and 21.8% during rotation. However, a statistically insignificant 37.2% increase was observed at the upper cervical spine (Oc-C2) during flexion-extension. The coupling pattern during rotation did not change significantly after laminoplasty.
In this first accurate documentation of 3D segmental kinematic changes after laminoplasty, Oc-T1 ROM, which represented total cervical ROM, did not change significantly during either flexion-extension or rotation by 6 months after laminoplasty despite a significant decrease in C2-7 flexion-extension ROM. This is thought to be partially because of a compensatory increase in segmental ROM at the upper cervical spine (Oc-C2).
颈椎椎板成形术是一种有效的多节段脊髓减压手术，但颈部活动受限是该手术常见的并发症之一。尽管许多作者报道了椎板成形术后颈椎活动范围（ROM）的情况，但他们主要关注的是侧位X线片上的二维屈伸活动，而非三维活动（包括耦合运动）或精确的椎间运动。本研究的目的是阐明为治疗脊髓型颈椎病而进行椎板成形术后颈椎的三维运动学变化。
本研究纳入了11例连续接受椎板成形术治疗脊髓型颈椎病的患者（6例男性，5例女性，平均年龄68.1岁，年龄范围57 - 79岁）。所有患者使用支撑装置在5个位置（中立位、头部左右旋转45°、最大头部前屈和最大头部后伸）进行颈椎的三维CT扫描。扫描在术前和椎板成形术后6个月进行。使用基于体素的配准方法计算从枕骨 - 寰椎（Oc - C1）到C7 - T1节段在屈伸和旋转时的ROM。
与之前所有研究中的颈椎ROM相当的C2 - 7屈伸ROM，术前为45.5°±7.1°，术后为35.5°±8.2°，术后有统计学意义的下降，降幅为33%。然而，代表整个颈椎ROM的Oc - T1屈伸ROM，术前为71.5°±8.3°，术后为66.5°±8.3°，下降了7.0%，无统计学意义。在关注每个运动节段时，作者观察到手术节段在屈伸时平均节段ROM有统计学意义的下降，降幅为22.6%，在旋转时下降了10.2%，无统计学意义。下降最显著的是在C2 - 3节段。C2 - 3节段在屈伸时ROM下降了24.2%，在旋转时下降了21.8%。然而，在上颈椎（Oc - C2）屈伸时观察到有统计学意义的37.2%的增加。椎板成形术后旋转时的耦合模式没有显著变化。
在首次对椎板成形术后三维节段运动学变化进行的准确记录中，代表整个颈椎ROM的Oc - T1 ROM在椎板成形术后6个月的屈伸或旋转过程中均未发生显著变化，尽管C2 - 7屈伸ROM有显著下降。这被认为部分是由于上颈椎（Oc - C2）节段ROM的代偿性增加。
