Wang Wei, Kong Chao, Pan Fumin, Wang Yu, Wu Xueqing, Pei Baoqing, Lu Shibao
Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing, China.
National Clinical Research Center for Geriatric Diseases, Beijing, China.
Front Bioeng Biotechnol. 2022 Aug 19;10:943092. doi: 10.3389/fbioe.2022.943092. eCollection 2022.
Although the management of the lumbar disease is highly dependent on the severity of the patient's condition, optimal surgical techniques to reduce the risk of adjacent degeneration disease (ADS) remain elusive. Based on biomechanical tests of the cadaver spine, this study aimed to comparatively analyze the kinematic responses of the spine with dynamic and rigid fixations (i.e., Coflex fixation and posterolateral fusion) after single-or double-level lumbar fusion in daily activities. Six human lumbar specimens (L1-S1) were selected for this experiment, and the sagittal parameters of each lumbar specimen were measured in the 3D model. The specimens were successively reconstructed into five groups of models: intact model, single-level L4-5 Coflex fixation model, single-level L4-5 Fusion (posterior pedicle screw fixation) model, double-level L4-5 Coflex + L5-S1 Fusion model; and double-level L4-5 Fusion + L5-S1 Fusion model. The pure moment was applied to the specimen model to simulate physiological activities in daily life through a custom-built robot testing device with an optical tracking system. For single-level lumbar fusion, compared to the traditional Fusion fixation, the Coflex dynamic fixation mainly restricted the extension of L4-L5, partially retained the range of motion (ROM) of the L4-L5 segment, and reduced the motion compensation of the upper adjacent segment. For the double-level lumbar fixation, the ROM of adjacent segments in the Coflex + Fusion was significantly decreased compared to the Fusion + Fusion fixation, but there was no significant difference. In addition, PT was the only sagittal parameter of the preoperative lumbar associated with the ROM under extension loading. The Coflex fixation had little effect on the original sagittal alignment of the lumbar spine. The Coflex was an effective lumbar surgical technique with a less altering kinematic motion of the lumbar both at the index segment and adjacent segments. However, when the Coflex was combined with the fusion fixation, this ability to protect adjacent segments remained elusive in slowing the accelerated degradation of adjacent segments.
尽管腰椎疾病的治疗高度依赖于患者病情的严重程度，但降低相邻节段退变疾病（ADS）风险的最佳手术技术仍不明确。基于尸体脊柱的生物力学测试，本研究旨在比较分析在日常活动中，单节段或双节段腰椎融合术后，脊柱在动态和刚性固定（即Coflex固定和后外侧融合）下的运动学反应。本实验选取了6个人类腰椎标本（L1-S1），并在三维模型中测量了每个腰椎标本的矢状面参数。标本依次重建为五组模型：完整模型、单节段L4-5 Coflex固定模型、单节段L4-5融合（后路椎弓根螺钉固定）模型、双节段L4-5 Coflex + L5-S1融合模型；以及双节段L4-5融合 + L5-S1融合模型。通过一个带有光学跟踪系统的定制机器人测试装置，将纯力矩施加到标本模型上，以模拟日常生活中的生理活动。对于单节段腰椎融合，与传统融合固定相比，Coflex动态固定主要限制了L4-L5的伸展，部分保留了L4-L5节段的活动范围（ROM），并减少了上相邻节段的运动代偿。对于双节段腰椎固定，与融合 + 融合固定相比，Coflex + 融合中相邻节段的ROM显著降低，但无显著差异。此外，PT是术前腰椎唯一与伸展负荷下的ROM相关的矢状面参数。Coflex固定对腰椎的原始矢状面排列影响较小。Coflex是一种有效的腰椎手术技术，对目标节段和相邻节段的腰椎运动学改变较小。然而，当Coflex与融合固定结合时，在减缓相邻节段加速退变方面，这种保护相邻节段的能力仍不明确。
