颈椎前路椎间盘切除融合术与人工颈椎椎间盘置换术治疗跳跃型颈椎椎间盘突出症的生物力学效应有限元分析

目的探讨颈椎前路椎间盘切除融合术(ACDF)和人工颈椎椎间盘置换术(CDA)治疗跳跃型颈椎椎间盘突出症的生物力学改变情况。方法建立正常人颈椎(C2~7)三维有限元模型,并与既往研究数据进行对比,验证模型的有效性。选择C3/C4和C5/C6建立节段跳跃ACDF(Zero-P系统)、跳跃CDA(Prestige-LP假体)模型。在混合负荷模式下,于模型C2齿突上施加75 N力负荷和1.0 N·m力矩作用,模拟颈椎的屈伸、侧曲、旋转等运动,对比分析正常颈椎、跳跃ACDF和跳跃CDA模型运动学与力学参数。结果与正常颈椎有限元模型相比,跳跃ACDF模型手术节段(C3/C4和C5/C6)各方向活动度(ROM)显著减少,中间节段(C4/C5)各方向ROM、椎间盘应力和小关节压力显著增加,其他非手术节段各方向ROM、椎间盘应力和小关节压力也有不同程度增加。跳跃CDA模型手术节段各方向ROM与正常模型相似,中间节段及其他非手术节段各方向ROM、椎间盘应力和小关节压力无明显改变。结论与跳跃ACDF相比,跳跃CDA对中间节段生物力学环境的影响更小,为CDA治疗跳跃型颈椎椎间盘突出症提供了生物力学依据。

Biomechanical analysis of anterior cervical discectomy and fusion versus cervical disc arthroplasty for skip-level cervical disc herniation: a finite element study

Objective To explore the biomechanical effect of anterior cervical discectomy and fusion(ACDF)versus cervical disc arthroplasty(CDA)for skip-level cervical disc herniation.Methods A finite element model of a healthy cervical spine(C2-7)was constructed and validated by comparing the flexion,extension,lateral bending and rotation against the literature data.After the validation of successful modeling,C3/C4 and C5/C6 were selected to establish the skip-level ACDF(Zero-P system)and skip-level CDA(Prestige-LP prosthesis)model.Hybrid loading conditions,under 1.0 N·m moments along flexion,extension,lateral bending and axial rotation with a compressive force of 75 N follower load in each direction,were applied on the top of the C2 vertebra in the study.Biomechanical and kinematic parameters such as ranges of motion(ROM),intradiscal pressure and facet joint forces were investigated and compared.Results In the ACDF model,the ROM of the operative segment(C3/C4 and C5/C6)were markedly decreased in all directions,while the ROM in all directions,intradiscal pressure and facet joint forces at the intermediate segment(C4/C5)were remarkably increased and unequally distributed among the non-operative segments compared with the normal finite element model.In the CDA model,the ROM of the operative segment were similar to those of normal finite element model,and the ROM in all directions,intradiscal pressure and facet joint forces at intermediate segment and other non-operative segments had no significant change.Conclusion Compared with skip-level ACDF,skip-level CDA has less impact on the biomechanical environment of the intermediate segment,which provides biomechanical basis for the treatment of skip-level cervical disc herniation with CDA.