Chen Chao, Yuchi Chen-Xi, Gao Ziwei, Ma Xinlong, Zhao Dong, Li Jun-Wei, Xu Baoshan, Zhang Chun-Qiu, Wang Zheng, Du Cheng-Fei, Yang Qiang
Department of Spine Surgery, Tianjin Hospital, Tianjin University, No. 406 Jiefangnan Road, Hexi District, Tianjin 300211, China.
Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China.
J Orthop Translat. 2020 Apr 2;23:107-112. doi: 10.1016/j.jot.2020.03.006. eCollection 2020 Jul.
Percutaneous full-endoscopic anterior cervical discectomy (PEACD) and posterior cervical foraminotomy (PCF) as alternatives to anterior cervical discectomy and fusion (ACDF) are extensively used in the treatment of patients with cervical spondylotic radiculopathy. The possibility of avoiding the risk of accelerated degeneration of the adjacent segments caused by fusion is claimed to be the theoretical advantage of these approaches; however, there is a paucity of supportive evidence from biomechanical data. Therefore, this study investigated and compared the effects of PCF, PEACD, and ACDF on the adjacent segments and operative segments of the cervical spine from a biomechanical standpoint.
A normal and intact three-dimensional finite element digital model of C4-C7 was constructed and validated, and the finite element models of PEACD, PCF, and ACDF were obtained by modifying the C4-C7 model. All models were exposed to identical conditions of load during flexion, extension, axial rotation, and lateral bending. We calculated the range of motion (ROM), intervertebral disc pressure (IDP), and facet joint contact force (FJCF) of the operative segment and the adjacent segment in different motion conditions.
The conventional ACDF had a remarkable influence on the ROM and IDP of the operative segment and the adjacent segments. In the PEACD model, the change of ROM was not noticeable; the IDP of the operative segment was significantly smaller, whereas the change of IDP of the adjacent segment was insignificant. In the PCF model, the ROM and IDP of all segments remained unaffected.During extension, the facet joint contact force changed significantly after ACDF, and it changed slightly after PECAD and PCF.
By comparatively analyzing the biomechanical changes of the cervical spine after PCF, PEACD, and ACDF using the finite element method, we suggested that PCF and PEACD were more suitable for surgical intervention of cervical spondylotic radiculopathy than ACDF from a biomechanical point of view and PCF may outperform PEACD.
经皮全内镜下颈椎前路椎间盘切除术（PEACD）和颈椎后路椎间孔切开术（PCF）作为颈椎前路椎间盘切除融合术（ACDF）的替代方法，被广泛用于治疗神经根型颈椎病患者。据称，避免融合导致相邻节段加速退变风险的可能性是这些方法的理论优势；然而，生物力学数据的支持证据却很少。因此，本研究从生物力学角度研究并比较了PCF、PEACD和ACDF对颈椎相邻节段和手术节段的影响。
构建并验证了一个正常完整的C4-C7三维有限元数字模型，并通过修改C4-C7模型获得了PEACD、PCF和ACDF的有限元模型。所有模型在屈曲、伸展、轴向旋转和侧屈过程中均承受相同的载荷条件。我们计算了不同运动条件下手术节段和相邻节段的活动度（ROM）、椎间盘压力（IDP）和小关节接触力（FJCF）。
传统的ACDF对手术节段和相邻节段的ROM和IDP有显著影响。在PEACD模型中，ROM的变化不明显；手术节段的IDP显著较小，而相邻节段的IDP变化不显著。在PCF模型中，所有节段的ROM和IDP均未受影响。在伸展过程中，ACDF后小关节接触力变化显著，而PECAD和PCF后变化轻微。
通过有限元方法比较分析PCF、PEACD和ACDF术后颈椎的生物力学变化，我们认为从生物力学角度来看，PCF和PEACD比ACDF更适合神经根型颈椎病的手术干预，且PCF可能优于PEACD。
