Adiposità interspinosa segno di instabilità vertebrale

We describe an 18-year-olkd woman with progressively worsening invalidating low back pain with functional limitation of the lumbar spine on x-ray. MR scans disclosed early disc degeneration and L5-S1 median posterior herniation possibly resulting from a complex bone-muscle-ligament malformation of the lumbosacral spine mainly characterised by an abnormal adipose-like signal in the L5-S1 interspinous region. Surgical findings confirmed the absence of the L5-S1 interspinous ligament and support the hypothesis that vertebral instability was the outcome. The literature was reviewed and the images of our case compared. We emphasize the role of MR scanning in spine disease and suggest that the images of all metameres should be assessed as a whole and correlated with the spine axis to disclose or rule out possible vertebral instability.