Yang K H, King A I
Spine (Phila Pa 1976). 1984 Sep;9(6):557-65. doi: 10.1097/00007632-198409000-00005.
Low-back pain has a complex and multi-faceted etiology. The articular facets have been shown to be load-bearing structures and may be a site for low-back pain. The aim of this paper is to establish the mechanism for the transmission of axial load across a facet joint and to propose a facet-related hypothesis for low-back pain. The mechanism of load transmission was studied by two methods. Lumbar segments were instrumented with an intervertebral load cell (IVLC) to measure disc load so that facet load could be deduced. The applied load was moved 10 mm anteriorly and 12.5 mm posteriorly from the center of the vertebral body. The facets then were separated from the body and loaded axially to determine their stiffness in tension and compression and to observe the failure mode of the joint. It was shown optically that compressive loading of the isolated facet joints was equivalent to spinal extension and tensile loading to spinal flexion. Lastly, a finite element model of a lumbar motion segment was developed to simulate the transmission of facet load and to study the effects of disc degeneration on facet loads. Results of the study on six lumbar segments revealed that the normal facets carried 3-25%. If the facet joint was arthritic, the load could be as high as 47%. Experiments on isolated facet joints revealed that they behaved as a stiffening spring in compression and were weak in tension.(ABSTRACT TRUNCATED AT 250 WORDS)
下背痛病因复杂且多方面。关节突已被证明是承重结构，可能是下背痛的一个发病部位。本文旨在确立轴向负荷通过关节突关节的传递机制，并提出一个与关节突相关的下背痛假说。通过两种方法研究负荷传递机制。在腰椎节段安装椎间盘负荷传感器（IVLC）来测量椎间盘负荷，从而推断关节突负荷。施加的负荷从椎体中心向前移动10毫米，向后移动12.5毫米。然后将关节突与椎体分离并轴向加载，以确定其拉伸和压缩刚度，并观察关节的失效模式。光学显示，孤立关节突关节的压缩负荷等同于脊柱伸展，拉伸负荷等同于脊柱屈曲。最后，建立了腰椎运动节段的有限元模型，以模拟关节突负荷的传递，并研究椎间盘退变对关节突负荷的影响。对六个腰椎节段的研究结果显示，正常关节突承受3% - 25%的负荷。如果关节突关节患有关节炎，负荷可能高达47%。对孤立关节突关节的实验表明，它们在压缩时表现为一个加强弹簧，在拉伸时较弱。（摘要截断于250字）
