Unsuspected damage to lumbar zygapophyseal (facet) joints after motor-vehicle accidents.

Three zygapophyseal joints from each of 31 lumbar spines of subjects who died of injuries (mostly as a result of motor-vehicle accidents) were sectioned for low-power histological study. Bony injuries, in the form of fractures of the superior articular process or infractions of the subchondral bone plate, were found in 11 of the 31 subjects and soft-tissue injuries to the capsule or articular cartilage were found in one-or-more joints in 24 of the 31 subjects, with capsular and articular-cartilage damage in 77% of cases. Healed injuries of a similar type, which were unrelated to the cause of death, were found in other lumbar spines. None of these lesions was diagnosed by standard radiological examination of the spine post mortem. It is suggested that, in survivors, bony and soft-tissue injuries to zygapophyseal joints may result in considerable pain and dysfunction and may predispose to early arthritis.