Spondylolysis and its relationship to degenerative joint disease in the prehistoric southeastern United States.

Spondylolysis, a fatigue fracture in the neural arch of lumbar vertebrae, is common in Eskimos and some athletes. In Archaic Indians from northwestern Alabama, 17% of males and 20% of females with complete lumbar regions showed this defect. It is found at a fairly early age in adult males in this group, but in females it does not appear until after age 40 years. Spondylolysis is associated with higher levels of osteoarthritis around the fifth lumbar vertebra, where this defect typically occurs. Otherwise, there is little relationship between its presence and degenerative joint disease, especially in the weight-bearing joints. The incidence in young males may be related to activities necessitating a high level of mobility around the lumbar spine. The late occurrence in females suggests that osteoporosis may have been a contributing factor.