目的 探究颈椎内镜下不同范围小关节切除对颈椎节段稳定性的影响，为临床手术提供生物力学理论基础。方法 基于CT数据建立颈椎C5~6正常有限元模型，并模拟颈椎内镜手术操作获得不同范围（0、25%、50%、75%、100%）单侧小关节切除椎板开窗模型（模型1~5），分析比较各组模型节段活动度（range of motion, ROM）及椎间盘von Mises应力情况。结果 除前屈工况外，模型1、2较正常模型各方向下ROM及椎间盘von Mises应力改变不明显，模型3较正常模型各方向下ROM及椎间盘von Mises应力出现较为明显增加，前屈、后伸、左侧弯、右侧弯、左旋转及右旋转时ROM分别增加27%、4%、3%、13%、5%、16%，von Mises应力分别增加32%、4%、2%、5%、9%、5%。模型4、5较正常模型各方向下ROM及椎间盘von Mises应力增加显著，模型4的ROM分别增加27%、14%、6%、24%、7%、167%，von Mises应力分别增加33%、13%、3%、32%、10%、130%；模型5的ROM分别增加27%、17%、6%、25%、7%、167%，von Mises应力分别增加33%、29%、8%、33%、12%、138%。结论 随着单侧小关节切除范围的增加，颈椎节段ROM和椎间盘von Mises应力极值逐渐增加。当单侧小关节切除超过1/2时，颈椎出现较大的ROM增加及应力改变。临床手术中应尽量保留1/2以上颈椎小关节，避免医源性失稳。

Objective To investigate the effect of facet joint resection at different ranges under endoscopy on the stability of the cervical spine and provide a biomechanical theoretical basis for clinical surgery. Methods A normal finite element model of The cervical spine C5-6 was established based on CT data, and unilateral facetectomy models with different ranges (0, 25%, 50%, 75%, and 100%) of laminectomy were obtained (Models 1-5) by simulating cervical endoscopic surgery. The ranges of motion (ROMs) of C5-6 and the von Mises stresses of the discs for the models in each group were compared and analyzed. Results Except for flexion, Models 1 and 2 showed insignificant changes in ROMs and disc von Mises stresses in each direction compared with those of the normal model. Model 3 showed a noticeable increase in ROMs and disc von Mises stresses in each direction compared with those of the normal model: ROMs under flexion, extension, left lateral bending, right lateral bending, left rotation, and right rotation increased by 27%, 4%, 3%, 13%, 5%, and 16%, respectively, and von Mises stresses increased by 32%, 4%, 2%, 5%, 9%, and 5%, respectively. Models 4 and 5 exhibited a significant increase in the ROMs and disc von Mises stresses in each direction compared to the normal model. For Model 4, ROMs were increased by 27%, 14%, 6%, 24%, 7%, 167%, and von Mises stress were increased by 33%, 13%, 3%, 32%, 10%, 130%. For Model 5, ROMs were increased by 27%, 17%, 6%, 25%, 7%, 167%, and von Mises stresses were increased by 33%, 29%, 8%, 33%, 12%, 138%. Conclusions As the range of unilateral facetectomy increased, cervical ROM and disc von Mises stress extremum gradually increased. The cervical spine shows a significant ROM increase and stress changes when facet joint resection on one side exceeds 1/2. More than 1/2 of the facet joint should be preserved during surgery to avoid medical instability.

国家自然科学基金项目（82274637）