A vertebral fracture in childhood is not a risk factor for disc degeneration but for Schmorl's nodes: a mean 40-year observational study

Abstract

Study design: Observational cohort study.

Objective: To evaluate by MRI whether a vertebral fracture during childhood is a risk factor for degeneration of adjacent discs.

Summary of background data: Several studies infer that trauma is a major cause of disc degeneration. Only 1 study has by magnetic resonance imaging (MRI) evaluated disc degeneration in children with a former thoracic or lumbar vertebral fracture. That study reported a 50% prevalence of degenerative disc changes 4 years after the fracture. However, due to the sparse literature, it is still unclear whether a vertebral fracture in childhood represents a risk factor for disc degeneration in a long-term perspective.

Method: Nine boys and 11 girls with a mean age of 12 years (range, 7-16 years) when sustaining a lumbar or thoracic vertebral fracture without neurologic deficits were examined at a mean of 40 years (range, 33-53 years) after the injury. Eighteen of the subjects had 1-column compression fractures, and 2 had Denis Type B burst fractures. All were mobilized without brace or surgery directly after being injured. A favorable long-term clinical and plain radiographic outcome has previously been reported for this cohort. In the present study, the intervertebral discs were evaluated with MRI by applying the Oner classification scheme. Degenerative disc changes were defined as loss of signal intensity on T2-weighted images with or without disc height reduction.

Results: Degenerative changes were not more prevalent in discs adjacent to the previously fractured vertebrae than in discs at a distance from those segments. However, there were more Schmorl's nodes at the disc levels adjacent to the earlier fractures.

Conclusion: Stable vertebral fractures in childhood with no neurologic deficits at injury do not render more degenerative changes than can be expected according to age, but they are associated with more Schmorl's nodes at adjacent disc levels.