Sun Chao, Li Yang, Feng Rongjie, Han Shijie
Department of Spinal Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University Jinan, Shandong Province, China.
Am J Transl Res. 2021 Nov 15;13(11):12714-12723. eCollection 2021.
To investigate the range of motion (ROM) index of a two-level cervical arthroplasty.
Seven human cadaveric spines were biomechanically examined from C2 level to T1 level under intact status and the following conditions: 2-level arthroplasty (C4-C6) employing Mobi-C devices (MM group), 2-level anterior cervical discectomy and fusions (2-ACDFs) (FF group), and both as a hybrid surgery (HS) (MF group and FM group). Multidirectional flexibility examination was conducted according to the Panjabi hybrid testing protocol. Unconstrained intact moments of ±1.5 NM were performed for axial rotation (AR) flexion/extension (FE), and lateral bending (LB).
No statistical differences were found between the intact spine and MM group at the operative- and adjacent-level kinematics in the three loading conditions, except that C4-C5 ROM significantly increased in the axial rotation loading (P<0.05). Compared with the intact spine, MF group led to a significant decrease at the arthrodesis segment ROM C5-C6 in the three loading (P<0.05), with corresponding significantly increased at C4-C5 in FE and AR (P<0.05). FM group resulted in a significant decrease in ROM C4-C5 (P<0.05) with corresponding significantly increased at C5-C6 in FE, AR and LB (P<0.05). There was not any difference for non-operative level kinematics between MF group and FM group and intact spine. Compared with the intact spine, FF group led to a significant decrease at the arthrodesis-levels (P<0.05) and marked increase at the non-operative level kinematics.
A two-level Mobi-C and Hybrid construct generated better biomechanical conditions. This study suggested that two-level cervical total disc replacement or HS could become an alternative approach for therapy of two-level consecutive cervical spondylosis.
研究两级颈椎置换术的活动范围（ROM）指标。
对7具人体尸体颈椎从C2水平至T1水平在完整状态及以下条件下进行生物力学检查：采用Mobi-C装置的两级置换术（C4-C6）（MM组）、两级颈椎前路椎间盘切除融合术（2-ACDFs）（FF组），以及两者作为混合手术（HS）（MF组和FM组）。根据Panjabi混合测试方案进行多方向灵活性检查。对轴向旋转（AR）、屈伸（FE）和侧弯（LB）施加±1.5牛米的无约束完整力矩。
在三种加载条件下，手术节段和相邻节段的运动学方面，完整脊柱与MM组之间未发现统计学差异，除了在轴向旋转加载时C4-C5的ROM显著增加（P<0.05）。与完整脊柱相比，MF组在三种加载下融合节段C5-C6的ROM显著降低（P<0.05），而在C4-C5的FE和AR中相应显著增加（P<0.05）。FM组导致C4-C5的ROM显著降低（P<0.05），而在C5-C6的FE、AR和LB中相应显著增加（P<0.05）。MF组和FM组与完整脊柱在非手术节段运动学方面没有差异。与完整脊柱相比，FF组导致融合节段显著降低（P<0.05），而非手术节段运动学显著增加。
两级Mobi-C和混合结构产生了更好的生物力学条件。本研究表明，两级颈椎全椎间盘置换或HS可能成为治疗两级连续性颈椎病的替代方法。
