Which Portion in a Facet is Specifically Affected by Articular Cartilage Degeneration with Aging in the Human Lumbar Zygapophysial Joint?

Abstract

Using 10 osteoligamentous vertebral columns obtained from elderly donated cadavers, we describe in detail degenerative changes of the articular cartilage in lumbar zygapophysial joints to show which portion in a facet is specifically affected. Degenerative changes, including extended cartilage defects, occurred in multiple facets of every specimen. The results demonstrated 5 basic morphologies of degeneration, i.e., 1) marginal dominace in the articular surface, 2) lower segment dominance except for the lowest (L5/S) facet, 3) advancement in the inferior articular process, 4) cranial and caudal dominance rather than the dorsal dominance in the articular surface and 5) progress in a mirror-image manner. These rules seemed to be consistent with differences in size, shape and kinesiological aspects of the facet between segments and between portions in a facet.