The characteristics of osteophyte around lumbar vertebral foramina associated with spinal stenosis.

Spinal stenosis most commonly occurs on lumbar vertebrae because of degenerative changes. This research studied the characteristics of osteophyte development in lumbar vertebrae foramina and association of osteophyte development with lumbar spinal stenosis. The total number of all levels of lumbar spines of subjects was 179 from 31 to 90 years of age. The vertebral foramen was divided into six zones. The prevalence and measurements of the length of osteophytes in the vertebral foramina were obtained. The prevalence and length of osteophytes in the posterior body zone were higher than the laminal zone, and higher than the pedicular zone, respectively. In each zone, the highest prevalence of osteophytes was at L5, except for the inferior posterior body zone that the highest prevalence is at L4. The length of osteophyte was also in same direction as the prevalence. The prevalence of osteophytes among six zones of each level were compared, and found, in L1 to L4, the inferior posterior body zone generally had the highest prevalence, except in L5, the superior posterior body zone had the highest prevalence. Moreover, prevalence, as well as length, of osteophytes in lumbar vertebral foramina, of all levels, was positively associated with age. Vertebral osteophytes can develop beginning at 31 years of age. In conclusion, posterior body of L4 and L5 had the highest prevalence of osteophyte formation, thus, these area had the highest probability to cause spinal stenosis.