课题背景：相邻节段病变是在脊柱植入各类内固定器材后长期随访中发现的一类临床问题。因此，如何选择内固定的范围对具有多节段退变的腰椎、颈椎病变是一个难题。近些年来人工椎间盘的出现为这类问题的解决提供了一条新道路，但这项技术的长期临床效果仍然有待观察。

应用要点：本实验利用了生物力学机模拟颈椎活动，并利用间盘测压仪对相邻节段的压力进行了系统对比测量。从实验结果分析，颈椎人工间盘确实可以减少一定的相邻节段的压力，与国外一些报道相似。

偏倚或不足：实验中如何更好地模拟颈椎在人体内的实际生理活动仍然是一个难点；如何用各种测量指标反映脊柱运动单元的应力变化也需多方面探索。

摘要

背景：颈椎内固定融合术后远期可出现相邻节段退变的现象，颈椎人工间盘置换术可能避免这种退变。
目的：对比颈椎人工间盘与颈椎内固定融合对颈椎相邻节段的生物力学影响。
设计、时间及地点：随机对照实验，于2007-08/2008-02在北京创伤骨科研究所生物力学实验室完成。
材料：新鲜羊颈椎标本18只，Bryan颈椎人工间盘由Medtronic公司生产，CSLP-VA颈椎内固定钛板由Synthes公司生产，珊瑚人工骨由意华健公司提供。
方法：将18只新鲜羊颈椎随机分为3组：①对照组：不处理。②人工间盘组：使用Bryan人工间盘置换及融合C5/6节段。③内固定组；切除C5/6间隙节段，间盘，去除椎体上下方的终板，置入珊瑚人工骨，采用CSLP-VA颈椎内固定钛板进行内固定。
主要观察指标：分别测量各组羊颈椎在一定负荷下屈曲，后伸，左右侧屈，左右旋转时的C5/6节段相邻间盘压力，对比各组之间相邻间盘的压力变化。
结果：①在C4/5节段，前屈时人工间盘组与对照组间盘压力相比无显著差异(P > 0.05)，而内固定组的间盘压力高于对照组 (P =0.035)。②在 C6/7节段，前屈时人工间盘组与对照组间盘压力相比无显著差异(P > 0.05)，而内固定组的间盘压力高于对照组(P =0.014)。其余后伸，旋转及侧屈时各组间无显著差异。
结论：与颈椎内固定术比较，颈椎人工间盘置换能在一定程度上降低颈椎相邻节段的间盘压力，起到避免相邻节段退变的作用。
关键词：人工间盘；生物力学；相邻节段；植入体

何达，韩骁，陶剑锋，田伟.颈椎人工间盘置换与颈椎内固定置入对相邻节段退变的生物力学影响[J].中国组织工程研究与临床康复，2008，12(22):4229-4232 [www.zglckf.com/zglckf/ejournal/upfiles/08-22/22k-4229(ps).pdf]

Effects of cervical total disc replacement versus anterior cervical discectomy and fusion on biomechanics of the segments adjacent to the operation level

Abstract
BACKGROUND: Long-term follow-up of the patients undergoing anterior cervical discectomy and fusion (ACDF) shows some incidence of degeneration at the segments adjacent to the fusion level. Cervical total disc replacement may resolve this problem.
OBJECTIVE: To compare the effects of cervical total disc replacement versus ACDF on the biomechanics of the segment adjacent to the operation level.
DESIGN, TIME AND SETTING: The randomized controlled trial was performed at biomechanical laboratory in Beijng Trauma and Orthopaedic Institute from August 2007 to February 2008.
MATERIALS: Eighteen samples of fresh goat cervical spine; Bryan artificial cervical disk (Medtronic); CSLP-VA cervical plate (Synthes); coral bone (Beijing Yihuajian Science And Trade Co., Ltd.).
METHODS: The goat spines were divided into 3 groups: control group with no specific treatment; total disc replacement group, in which C5/6 segment underwent Bryan artificial cervical disk replacement and fusion; internal fixation group, in which the C5/6 segment underwent cervical discectomy, coral bone implantation and internal fixation with CSLP-VA cervical plate.
MAIN OUTCOME MEASURES: The adjacent intervertebral disk pressure (IDP) was measured in flexion, extension, rotation and lateral bending under certain loading, and the pressure changes were compared among three groups.
RESULTS: At level C4/5, the IDP between total disk replacement group and the control group had no statistical significances in flexion (P < 0.05), but that of internal fixation group was significantly higher than that of control group (P=0.035). At level C6/7, there were no significant differences in IDP between total disk replacement group and control group in forward flexion (P > 0.05), but internal fixation group was significantly higher than control group (P=0.014). There were no significant differences among the three groups in IDP in extension, rotation and lateral bending.
CONCLUSION: Compared with ACDF, the total disk replacement can reduce the adjacent segment IDP and may avoid the degeneration in adjacent cervical segment.

He D, Han X, Tao JF, Tian W.Effects of cervical total disc replacement versus anterior cervical discectomy and fusion on biomechanics of the segments adjacent to the operation level.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(22):4229-4232 [www.zglckf.com/zglckf/ejournal/upfiles/08-22/22k-4229(ps).pdf]