High lumbar disc degeneration. Incidence and etiology.

Three hundred seventy-nine consecutive magnetic resonance images (MRIs) with dual-echo images of the entire lumbar spine were reviewed by the authors. All 379 patients presented with back pain and/or leg pain; they were interviewed and examined. Pain drawings were completed by all. There were 42 patients (11.1%) with disc pathologies involving T12-L1, L1-2, and/or L2-3 levels. Six patients (1.6%) had isolated disc degeneration and/or herniations limited only to these high lumbar segments. The remaining 36 patients had degenerative changes of the higher discs with variable involvement of the lower lumbar discs. Out of 12 spondylolistheses of L5 on S1, 7 had high disc pathologies at one or more levels presenting as skipped lesions; more severe high disc lesions were noted in Grade II slips. Isolated high disc degeneration is often associated with pre-existing abnormalities such as end-plate defects, Scheuermann's disease, limbus vertebra, and so forth, and stressful cumulative work activities such as in construction workers, airplane mechanics, and so forth. High disc degeneration was noted above or below previous fractures. High disc involvement with diffuse changes in lower lumbar spine was more commonly found in ascending fashion in older age groups, and in patients who have had previous lower lumbar spine surgeries, prior fusions in particular. Our findings suggest that altered mechanics are associated with the high lumbar disc pathologies.