The prevalence of disc degeneration associated with neural arch defects of the lumbar spine assessed by magnetic resonance imaging.

The morphology of the intervertebral discs in 40 patients with spondylolytic and mild spondylolisthetic defects of the lumbar spine were assessed using magnetic resonance imaging. The results were compared with an age- and sex-matched asymptomatic population, and the difference in prevalence of disc degeneration between the two groups was noted. Under the age of 25 years, degeneration was uncommon in both the disc associated with the neural arch defect and the comparable disc in the control population. However, after this age, the prevalence of the disc degeneration rose in both groups, but was more marked in the spondylytic group, and this difference was statistically significant (P = 0.025). The results suggest that a neural arch defect is associated with an increased prevalence of disc degeneration, which is greater than is seen in a normal aging population.