Macroscopic anatomy of the vertebral endplate: quid significat?

Alterations of vertebral endplates have long been a subject of interest, but are of unclear clinical significance. The vertebral columns of a cohort-based sample of 850 individuals were therefore evaluated for vertebral endplate defects, noting adjacent vertebral size and shape variation, bone density and associated pathologies. Defects were found in the vertebral endplates of 458 individuals (Schmorl's nodes in 52.0% and linear defects in 10.6%). Vertebral centra osteophytes and diffuse idiopathic skeletal hyperostosis were more common; vertebral compression, less common in vertebrae with defects. Linear defects were more disseminated throughout the vertebral column, with individual defects more commonly affected either the interior half or the posterior quarter of the endplate or extended across all quarters form anterior to posterior. Individual Schmorl's nodes were predominantly limited to a single quarter. An inverse relationship was identified with tuberculosis. Spondyloarthropathy was more common in individuals with Schmorl's nodes, but not linear defects. Schmorl's nodes and linear endplate defects should be independently assessed, although they do share implications. Paradoxically, they are associated with phenomena which seem to mark increased ossification potential (osteophytes and diffuse idiopathic skeletal hyperostosis), but not with osteoporosis. Similarly, presence of Schmorl's nodes correlation with spondyloarthropathy, another disorder characterized by increased ossification potential. While correlation is not causality, inverse relationship to tuberculosis is intriguing, given the known relationship of spondyloarthropathy to tuberculosis and its antigens. Previously undescribed surface elevations were commonly associated with the presence of Schmorl's nodes and also correlated with disease, especially inflammatory arthritis, hypertrophic osteoarthropathy.