Normal variations of the lumbar facet joint capsules

The anatomy and variations of the lumbar facet joint capsules have not been described in detail. Fifty lumbar cadaver facet joints were studied with cryomicrotomy. The axial sections were analyzed to describe the normal appearance of the facet joint capsule. In the majority of cases the facet joint capsule extended beyond the confines of the borders of the facet joint proper. The most common patterns were extensions along the inferior articular process near the dorsal or along the inferior or superior articular process in the ventral aspect of the joint. The study extends previous anatomic studies on the facet joint capsule.