目的:优化"人工颈椎复合关节系统"("artificialcervical joint complex"ACJC)并进行生物力学评价.方法:在前期设计的基础上,以及通过测量工作得到的关于正常人体颈椎解剖和运动学参数,优化ACJC.新鲜的人体颈椎标本14具,随机取出7具作为正常颈椎组,在MTS 858 Mini Bionix Ⅱ生物材料实验系统进行稳定性实验并测定各节段椎间活动度.随后将标本随机分为钢板固定组和假体植入组,每组7例,对每组标本分别进行实验前处理:钢板固定组依次行前路C5椎体次全切、植骨融合内固定术;假体植入组依次行C5椎体次全切、假体植入术.试验同正常颈椎组.结果:稳定性实验显示假体植入组与正常颈椎组相比,下颈椎在三维六自由度的ROM均无显著差异.而钢板固定组在前屈、后伸、左右侧弯中的活动范围(ROM)均小于显著其余两组.手术节段活动度测定显示,钢板固定组的各向ROM均显著小于其余两组,而假体植入组仅在后伸运动中ROM显著大于正常颈椎组,其余活动中均与正常颈椎组无显著差异.临近椎间活动度测定显示,三组间下位椎间隙活动度无显著差异;对于上位椎间隙,假体植入组与正常颈椎组无显著差异.钢板固定组前屈、后伸活动度均较其余两组显著增大.结论:应用该系统进行颈椎前柱重建,既重建了颈椎稳定性,又一定程度地保留了手术节段活动度,更符合颈椎生理性重建的要求.同时该方法避免了手术邻近节段椎间隙活动代偿性增大,对避免远期邻近节段退变加速可能具有重要意义.
Optimal design and biomechanical assessment of "artificial cervical joint complex"
AIM: To optimze the design and perform biomechanical assessmen 1 of "artificial cervical joint complex". METHODS: Based on the geometric and movement parameters of human' cervical spine, we optimized and manufactured "artificial cervical joint complex" (ACJC) with titanium alloy. Drawing out 7 samples of 14 fresh cervical spines as intact group randomly, carried on the experiments on stability under the biomaterial experimental system of MT3 858 Mini Bionix Ⅱ. Divided 14 cervical spines into 2 groups including plate-screw fixation group and prosthesis-implanted group averagely and randomly, then tackled them before experiment respectively: conduct anterior C5 subtotal corpectomy, bone graft fusion and internal fixation by turns for the plate-screw fixation group; conduct C5 subtotal corpectomy and prosthesis implantation by turns for the prosthesis-implanted group, carried on the same experiments as the intact group. RESULTS: Inter-vertebral motion was obtained with"ball-socket and chute joint" pattern. With simple structure it owns good mechanical stability. As for the lower cervical spine, there was no apparent difference between prosthesis-implanted group and intact group in the three-dimension ROM. While in the plate-screw fixation group, ROM is smaller in the flexion, extension and lateral curvature compared with the prosthesis-implanted group and the intact group, with no difference in lateral bending. As for the surgical segment, ROM of the plate-screw fixation group is smaller in the three-dimensions ROM obviously compared with the prosthesis-implanted group and the intact group. ROM of the prosthesis-implanted group is the same in most of the activities as of the intact group while larger in the extension. ROM of the plate-screw fixation group in flexion and extension is larger than the rest two groups without difference in lateral betiding. CONCLUSION: Using ACJC to reconstructing cervical spine following subtotal corpectomy, can either restore segmental motion or regain almost the same stability as in intact condition. Compared with the standard bone graft and plate-screw internal fixation, it fits the requirements of physiological reconstruction more and steps towards physiological reconstruction of the cervical spine technically, which offers a new option for the reconstruction of cervical spine in the future. Meanwhile, it avoids abnormal increase of inter-vertebral ROM in the adjacent segment, which may make sense of prevention of long-term acceleration of degeneration of adjacent segments.
NETL
NSTL
万方数据
