颈椎前路一体化钢板椎间融合器置入后与颈椎生物力学环境的匹配

背景：研究表明，颈椎一体化前路钢板融合器比现行钢板和融合器具有更多理论上的优势。但是目前有关其生物力学方面的研究国内尚无文献报道。 目的：观察与评价颈椎前路一体化钢板椎间融合器内固定置入后的生物力学特征。 方法：采集6具成人尸体颈椎标本，分为5组进行测试，即正常组、椎间盘摘除组、颈椎前路一体化钢板椎间融合器固定组、CBK融合器固定组及CBK融合器+Secuplate钢板联合固定组，以C5~6椎间隙为观察对象，进行生物力学实验。 结果与结论：颈椎间盘摘除后，颈椎在各个方向运动加大，刚度及强度等生物力学数值减小，脊柱失稳。与椎间盘摘除组相比，颈椎前路一体化钢板椎间融合器固定后其强度增加24%，椎体应变减小31%，刚度增加14.3%，位移减小15%(P < 0.05)，颈椎前路一体化钢板椎间融合器对颈椎的力学性能影响较小，说明它能较好地与颈椎的力学环境相匹配。CBK融合器固定后抗后伸及旋转作用相对较小，同椎间盘摘除组相比差异有显著性意义(P < 0.05)。CBK融合器+Secuplate钢板联合固定组载荷强度和应变过大，与椎间盘摘除组相比其强度增加27%，椎体应变减小38%，刚度增加17%，位移减小17% (P < 0.05)，颈椎刚度增大且邻近椎节的运动有增大趋势，将引起力学性能的改变。提示颈椎前路一体化钢板椎间融合器结合了颈椎前路钢板和融合器生物力学方面的优点，能较好地与颈椎的力学环境相匹配。

Matching between intergrated anterior cervical plate cage benezech implant and biomechanical environment

BACKGROUND: Studies demonstrated that intergrated anterior cervical plate cage benezech implant (PCB) superior to used plates and fusion cage theoretically. However, reports concerning biomechanical analysis of the PCB are few. OBJECTIVE: To investigate biomechanical characteristics of the PCB. METHODS: Five types were made in 6 adult cadaveric cervical spines: normal, simulated vertebral disc removal, PCB fixation, CBK fusion cage fixation, CBK fusion cage and Secuplate titanium plate conjoined fixation. Their stability was tested by experimental stress analysis at C5-6. RESULTS AND CONCLUSION: The cervical spine became unstable and the range of motion increased significantly after the removal of vertebral disc. Compared with simulated vertebral disc removal group, after instrumentation of cervical PCB fixation, the strength increased 24%, the flexibility decreased 31%, the stiffness increased 14.3%, and the migration decreased 15% (P < 0.05). There was significant difference between the PCB fixation group and simulated vertebral disc removal one (P < 0.05). And the range of motion of the cervical spine after the insertion of correct size of PCB was similar to that of intact condition. The CBK fusion cage group was unsatisfied under extension and torsion tests, but there was significant difference between CBK fusion cage fixation group and simulated vertebral disc removal one (P < 0.05). Compared with simulated vertebral disc removal group, after instrumentation of cervical CBK fusion cage and Secuplate titanium plate conjoined fixation, the strength increased 27%, the flexibility decreased 38%, the stiffness increased 17%, and the migration decreased 17% (P < 0.05). But the motion of the segment following insertion of CBK fusion cage and Secuplate titanium plate conjoined fixation almost lost and the range of motion of the adjacent segment increased. PCB has occupied advantages of both secuplate titanium plate fixation and CBK fusion cage fixation which could match the biomechanical environment.