Department of Neurosurgery, 3 Silverstein Hospital of the University of Pennsylvania, 3400 Spruce St., Philadelphia, PA 19104, USA.
Spine J. 2012 Oct;12(10):949-59. doi: 10.1016/j.spinee.2012.08.013. Epub 2012 Sep 10.
Total disc arthroplasty is a motion-preserving spinal procedure that has been investigated for its impact on spinal motions and adjacent-level degeneration. However, the effects of disc arthroplasty on facet joint biomechanics remain undefined despite the critical role of these posterior elements on guiding and limiting spinal motion.
The goal was to measure the pressure in the facet joint in cadaveric human cervical spines subjected to sagittal bending before and after implantation of the ProDisc-C (Synthes Spine Company, L.P, West Chester, PA, USA).
A biomechanical study was performed using cadaveric human cervical spines during sagittal bending in the intact and implanted conditions.
Seven C2-T1 osteoligamentous cadaveric cervical spines were instrumented with a transducer to measure the C5-C6 facet pressure profiles during physiological sagittal bending, before and after implantation of a ProDisc-C at that level. Rotations of the index segment and global cervical spine were also quantified.
The mean C5-C6 range of motion significantly increased (p=.009) from 9.6°±5.1° in the intact condition to 16.2°±3.6° after implantation. However, despite such changes in rotation, there was no significant difference in the facet contact pressure during extension between the intact (64±30 kPa) and implanted (44±55 kPa) conditions. Similarly, there was no difference in facet pressure developed during flexion.
Although implantation of a ProDisc-C arthroplasty device at the C5-C6 level increases angular rotations, it does not significantly alter the local facet pressure at the index level in flexion or extension. Using a technique that preserves the capsular ligament, this study provides the first direct measurement of cervical facet pressure in a disc arthroplasty condition.
全椎间盘置换术是一种保留运动的脊柱手术，已对其对脊柱运动和相邻节段退变的影响进行了研究。然而，尽管这些后部元素对指导和限制脊柱运动起着关键作用，但椎间盘置换术对小关节生物力学的影响仍未确定。
目的是测量 ProDisc-C（Synthes Spine Company，LP，宾夕法尼亚州西切斯特，美国）植入前后尸体人颈椎矢状弯曲时小关节内的压力。
在完整和植入条件下，对尸体人颈椎进行矢状弯曲的生物力学研究。
7 具 C2-T1 骨韧带颈椎尸体标本，在生理矢状弯曲过程中，在 C5-C6 小关节处用换能器测量压力分布，在该水平植入 ProDisc-C 前后。还定量了索引节段和整个颈椎的旋转。
平均 C5-C6 运动范围明显增加（p=.009），从完整状态下的 9.6°±5.1°增加到植入后的 16.2°±3.6°。然而，尽管旋转发生了这些变化，但在伸展时完整（64±30 kPa）和植入（44±55 kPa）状态下小关节接触压力没有显著差异。同样，在弯曲时也没有产生不同的小关节压力。
虽然在 C5-C6 水平植入 ProDisc-C 关节置换装置会增加角度旋转，但在弯曲或伸展时不会显著改变指数水平的局部小关节压力。使用一种保留囊韧带的技术，本研究首次直接测量了椎间盘置换术中颈椎小关节的压力。
