Schmorl Nodes, Disc Degeneration, and Pain

Abstract

Schmorl nodes (SNs) of the lumbar spine are an ill-defined entity sometimes referred to as intravertebral disc herniation and by others as end plate irregularities. They are often considered a radiographic curiosity with no clinical consequences. As part of a large-scale population-based study of the Hong Kong Degenerative Disc Disease cohort, sagittal T2-weighted magnetic resonance images of the lumbar spine were analyzed in 2,499 volunteers. SNs were found in 16.4% of the study population, being most common at L1/2 and L2/3 (54.1%). Multivariate logistic regression revealed that males, taller and heavier individuals had an increased likelihood of SN ( p < 0.005), suggesting mechanical factors may play a role in their pathogenesis. On the contrary, SNs were independent of age. Overall presence of SN was associated with disc degeneration ( p < 0.001), and linearly correlated ( R2 = 0.97) with increase in severity of degeneration. SN were particularly associated with severe disc degeneration at L1/2 and L2/3 with 22- to 15-fold increased odds, respectively ( p < 0.0001), but less than 5-fold increased odds ( p < 0.001) were noted in the lower lumbar spine. This presentation will discuss the various radiologic appearances of end plate irregularities that may be considered as SNs and propose a new classification based on morphology. In addition, morphological patterns tend to cluster in a particular manner to suggest different etiological factors may be associated with different subtypes of SNs. The relevance of end plate changes in the etiology of lumbar disc degeneration will also be discussed. Disclosure of Interest None declared