Puttlitz Christian M, Rousseau Marc Antoine, Xu Zheng, Hu Serena, Tay Bobby K-B, Lotz Jeffrey C
Orthopaedic Biomechanics Laboratory, San Francisco General Hospital, and the Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA 94110, USA.
Spine (Phila Pa 1976). 2004 Dec 15;29(24):2809-14. doi: 10.1097/01.brs.0000147739.42354.a9.
An in vitro biomechanical study of C4-C5 intervertebral disc replacement using a cadaveric model.
To investigate the degree of motion afforded by a ball-and-socket cervical intervertebral disc prosthesis design.
Intervertebral disc prostheses designs attempt to restore or maintain cervical disc motion after anterior cervical discectomy and reduce the likelihood of accelerated degeneration in adjacent discs by maintaining normal motion at the affected disc level. Surprisingly, the actual kinetic and biomechanical effects that cervical disc arthroplasty imparts on the spine have not been widely reported. Accordingly, we investigated what effect implanting a cervical disc prosthesis has on the range of motion at the affected level as well as how it changes the coupled motion patterns at the level of implantation.
Six fresh-frozen human cadaveric cervical spines (C2-C7) were used in this study. We evaluated two different spinal conditions: intact and after disc replacement at C4-C5. Compression (using the follower load concept) and pure moment loading were applied to the specimen. Range of motion was measured using an optical tracking system. Statistical differences between the intact and replaced condition range of motion was determined using analysis of variance with post hoc comparisons (alpha = 0.05).
The data indicate that the intervertebral disc prosthesis approximated the intact motion in all three rotation planes at the affected level. Finally, changes in cervical coupled rotations, specifically lateral bending during axial rotation loading and axial rotation during lateral bending loading, were not statistically significant between the two tested conditions.
Our data demonstrate that a ball-and-socket design can replicate physiologic motion at the affected and adjacent levels. More importantly, the data indicate that motion coupling, which is most dramatic in the cervical spine and plays an important biomechanical role, is maintained.
使用尸体模型对C4 - C5椎间盘置换进行体外生物力学研究。
研究球窝式颈椎间盘假体设计所提供的活动度。
椎间盘假体设计旨在在前路颈椎间盘切除术后恢复或维持颈椎间盘活动，并通过在受影响椎间盘水平维持正常活动来降低相邻椎间盘加速退变的可能性。令人惊讶的是，颈椎间盘置换术对脊柱实际的动力学和生物力学影响尚未得到广泛报道。因此，我们研究了植入颈椎间盘假体对受影响节段活动范围的影响，以及它如何改变植入节段的耦合运动模式。
本研究使用6个新鲜冷冻的人类尸体颈椎（C2 - C7）。我们评估了两种不同的脊柱状态：完整状态和C4 - C5椎间盘置换后状态。对标本施加压缩（采用跟随载荷概念）和纯弯矩载荷。使用光学跟踪系统测量活动范围。使用方差分析及事后比较（α = 0.05）确定完整状态和置换状态活动范围之间的统计学差异。
数据表明，椎间盘假体在受影响节段的所有三个旋转平面上接近完整运动。最后，在两种测试状态之间，颈椎耦合旋转的变化，特别是轴向旋转加载时的侧弯和侧弯加载时的轴向旋转，在统计学上无显著差异。
我们的数据表明，球窝式设计可以在受影响节段和相邻节段复制生理运动。更重要的是，数据表明在颈椎中最为显著且起重要生物力学作用的运动耦合得以维持。
