Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.
Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
J Orthop Res. 2023 Mar;41(3):674-683. doi: 10.1002/jor.25407. Epub 2022 Jul 9.
The zygapophyseal joints of the spine, also known as the facet joints, are paired diarthrodial joints posterior to the intervertebral disc and neural elements. The pathophysiology of facet osteoarthritis (OA), as well as crosstalk between the disc and facets, remains largely understudied compared to disc degeneration. The purpose of this study was to characterize alterations to human facet cartilage and subchondral bone across a spectrum of degeneration and to investigate correlations between disc and facet degeneration. Human lumbar facet articular surfaces from six independent donors were subject to creep indentation mechanical testing to quantify cartilage mechanical properties, followed by microcomputed tomography (µCT) analyses for subchondral bone morphometry. The degenerative state of each articular surface was assessed via macroscopic scoring and via Osteoarthritis Research Society International histopathology scoring. Our data suggest reduced facet cartilage compressive and tensile moduli and increased permeability with increasing degenerative grade, particularly at the lower levels of the spine. µCT analyses revealed spinal level-dependent alterations to the subchondral bone, with an increase in trabecular bone at the L4-L5 level, but a decrease at the upper levels of the lumbar spine with increasing degenerative grade. Cortical bone volume fraction was generally decreased with increasing degenerative grade across spinal levels. Correlation analysis revealed several associations between quantitative measures of disc degeneration and facet OA. This study showed that alterations in the mechanical properties of facet cartilage and in the structural properties of facet subchondral bone correlated with aspects of disc degeneration and were highly dependent on spinal level.
脊柱的关节突关节，也称为关节突关节，是位于椎间盘和神经结构后方的成对滑膜关节。与椎间盘退变相比，关节突关节炎（OA）的病理生理学以及椎间盘和关节突之间的串扰在很大程度上仍未得到充分研究。本研究的目的是描述人关节突软骨和软骨下骨在退变谱中的变化，并研究椎间盘和关节突退变之间的相关性。来自六个独立供体的人腰椎关节突关节表面接受了蠕变压痕力学测试，以量化软骨力学特性，然后进行微计算机断层扫描（µCT）分析以进行软骨下骨形态计量学分析。通过宏观评分和骨关节炎研究协会国际组织病理学评分评估每个关节表面的退行性状态。我们的数据表明，随着退行性分级的增加，关节突软骨的压缩和拉伸模量降低，渗透性增加，尤其是在脊柱的较低水平。µCT 分析显示，软骨下骨随脊柱水平的变化而发生变化，在 L4-L5 水平，小梁骨增加，但随着退行性分级的增加，腰椎上部的小梁骨减少。皮质骨体积分数通常随退行性分级的增加而降低。相关性分析显示椎间盘退变的定量测量与关节突 OA 之间存在多种关联。这项研究表明，关节突软骨的力学性能改变和关节突软骨下骨的结构特性改变与椎间盘退变的某些方面相关，并且高度依赖于脊柱水平。
