Successive thoracic anterolateral intervertebral disc herniations with ossification-fusion: a cadaveric case analysis with MRI and clinical review

Background: Intervertebral discs (IVDs) permit resilient deformability and shock absorption between vertebrae. IVD herniation from damage or disease most commonly occurs in the lumbar and cervical spines, in the posterolateral direction, and to a single IVD. This investigation seeks to examine a unique case of successive thoracic anterolateral IVD herniations with gross and magnetic resonance imaging (MRI) analyses and present the case with a literature-based clinical narrative. Methods: The case was discovered in an adult human cadaver. T1-weighted MRI was performed on the implicated spine, and serial cross-sectioning was completed through each IVD. The herniations were photographed at each stage, and linear parameters of the spinal pathologies were measured. Results: The ossified herniations extruded 11.1 ± 2.1 mm from the typical IVD border, and the ossified bridging over the vertebral bodies extruded 6.9 ± 2.6 mm from the typical vertebral body border. The extrusions displaced the functionality of the anterior longitudinal ligament 7.37 mm left of midline, and comparison of gross in situ and cross-sectional imaging with MRI illustrated the extent of IVD herniation and vertebral fusion in the clinical perspective. Conclusions: The present cadaveric case involving multiple uncommon features of IVD herniation accompanied by MRI and clinical narrative may enhance clinical awareness among spine specialists, particularly in recognizing uncommon presentations of thoracic IVD ossification and vertebral hyperostosis. This report may also serve as a valuable reference for to clinical anatomists, Doctors of Chiropractic Medicine, spine neurosurgeons, and other healthcare experts when discussing or treating related patient cases.