Relationship of Schmorl's nodes to vertebral body endplate fractures and acute endplate disk extrusions

BACKGROUND AND PURPOSE: Literature regarding clinical pain syndromes associ ated with acute, traumatic Schmorl's nodes (SNs) is limited. Our purpose wa s to determine whether an SN could be related to a previous traumatic event producing either acute SN or a vertebral endplate fracture. METHODS: Two neuroradiologists independently reviewed initial and follow-up MR examinations of 14 patients with a clinical diagnosis of acute, symptom atic thoracolumbar SNs or vertebral body endplate fractures that evolved in to SNs to evaluate marrow edema, signal intensity, margin definition, prese nce of intravertebral extruded disk material, and pattern of contrast enhan cement. RESULTS: Edema of the affected vertebral body, adjacent to an endplate with out wedging or collapse, was observed on the initial MR images in all cases . The initial MR images of six (43%) of 14 patients exhibited only edema of the marrow immediately adjacent to the endplate without wedging or collaps e. The MR images obtained at the time of follow-up showed subsequent format ion of a chronic and eventually asymptomatic SN for all six patients. The i nitial MR images of eight (57%) of the 14 patients showed the typical appea rance of acute SNs with marrow edema of the affected vertebra, The contrast -enhanced images of three patients manifested enhancement of the invaginate d disk material in three (100%) of three cases and enhancement of the surro unding vertebral body in one case (33%). Six (43%) of 14 patients had acute typical compression fracture of a vertebral body of at least one additiona l level. CONCLUSION: Most (57%) of the SNs in this series could be traced to episode s of significant, sudden-onset, localized, nonradiating back pain and tende rness for which the MR images showed SNs surrounded by vertebral body marro w edema. The remaining SNs (43%) were not immediately apparent as SNs and m anifested only as vertebral body edema representing endplate fracture but d id evolve into classical chronic SNs that follow-up imaging revealed.