Lumbar osteoporotic fractures develop in segments with less degenerated discs which then become more degenerated.

Abstract

Our aim was to study the influence of segmental variations in intervertebral disc degeneration on the location of acute osteoporotic compression fractures and to investigate chronic effect of such fractures on adjacent discs. This retrospective study included 83 patients (69 females; mean ± SD age: 72.3 ± 14.0years) with osteoporotic vertebral fractures. Using lumbar MRI, two neuroradiologists evaluated 498 lumbar vertebral segments for the presence and acuity of fractures and graded adjacent intervertebral disc degeneration on Pfirrmann's scale. Absolute and relative (to average patient-specific degeneration grade) segmental degeneration grades were compared against the presence and chronicity of vertebral fractures for all segments and for upper (T12-L2) and lower (L3-L5) subgroups. Intergroup analysis was conducted using Mann-Whitney U tests, withpvalue of < .05 considered significant. Fractures involved 149/498 (29.9%; 15.1% acute) vertebral segments, majority (61.1%) involving T12-L2 segments. Segments with acute fractures had significantly lower degeneration grades (mean ± SD: absolute: 2.72 ± 0.62; relative: 0.91 ± 0.17) than those with no (absolute: 3.03 ± 0.79, p = 0.003; relative: 0.99 ± 0.16, p < 0.001) or chronic fractures (absolute: 3.03 ± 0.62, p = 0.003; relative: 1.02 ± 0.16, p < 0.001). Degeneration grades were higher in the lower lumbar spine (p < 0.001) in the absence of fractures, but comparable to upper spine for segments with acute or chronic fractures (p = 0.28 and 0.56, respectively). Osteoporotic vertebral fractures favour segments with lower burden of disc degeneration, but likely contribute to subsequent worsening of adjacent disc degeneration.