Pathoanatomic studies and clinical significance of lumbosacral zygapophyseal (facet) joints.

Low back pain, with or without pain referred to the leg, affects up to 85% of the population at some time during their lives, which places an enormous economic burden upon many world communities and costs the United States in excess of $13 billion per year. The role of the lumbosacral zygapophyseal (facet, interlamina) joints in the low back "facet" syndrome is briefly discussed, including the clinical symptomatology. The main purpose of this article is to provide preliminary morphological findings of histological studies of human cadaveric lower lumbosacral spines, which show some examples of how the zygapophyseal joints may be involved in dysfunction of mechanical origin. Statistical analysis of the frequency of these findings will be published when the histological study currently under way is completed. While it is not possible to correlate morphological changes in cadavers with pain, it appears that the zygapophyseal joints and their associated soft tissues could be a source of low back pain of mechanical origin, with or without referred pain to the leg.