Thoracic Disc Herniation¶

Definition¶

Thoracic disc herniation is the displacement of disc material beyond the normal margin of the intervertebral disc space in the thoracic spine. It is relatively uncommon compared to cervical and lumbar herniations due to the stabilizing effect of the rib cage and the coronal facet orientation limiting flexion-extension motion.

Epidemiology¶

Accounts for only 1–3% of all symptomatic disc herniations
Most common levels: T8–T12 (lower thoracic, near the thoracolumbar junction)
Incidental thoracic disc herniations are found in up to 37% of asymptomatic individuals on MRI
Peak age: 40–60 years

Clinical Significance¶

The thoracic spinal canal is the narrowest relative to cord size, with the least amount of epidural space buffer
Even small herniations can cause significant cord compression
Thoracic herniations can cause myelopathy — progressive lower extremity weakness, spasticity, gait difficulty, and bowel/bladder dysfunction
Calcified herniations are more common in the thoracic spine than elsewhere and may require anterior surgical approach

Imaging Findings¶

MRI¶

Sagittal T2: disc extension into the spinal canal; assess cord compression and cord signal
Axial T2: characterize location (central, paracentral, lateral) and cord deformation
Cord T2 hyperintensity at the level of herniation indicates myelopathy
Calcified components may appear low signal on all MRI sequences — CT may be needed to confirm calcification

CT¶

Superior for detecting calcified herniations — important for surgical planning
Calcified herniations may require anterior approach (transthoracic) rather than posterior laminectomy to avoid cord manipulation

Clinical Pearl

Many thoracic disc herniations are incidental findings and are asymptomatic. However, the narrow thoracic canal means that symptomatic thoracic herniations can progress to severe myelopathy. Any thoracic herniation with cord compression and T2 signal change in the cord should be taken seriously regardless of current symptom severity — these patients need close follow-up and often surgical referral.

Key Points¶

Thoracic herniations are uncommon (1–3% of symptomatic herniations) but often incidental
Most common at T8–T12 near the thoracolumbar junction
The narrow thoracic canal means even small herniations can compress the cord
Calcified herniations are more common in the thoracic spine — CT helps confirm
Cord signal change on MRI indicates myelopathy and warrants close follow-up or surgery

References¶

Cornips EMJ, Janssen MLF, Beuls EAM. Thoracic disc herniation and acute myelopathy: clinical presentation, neuroimaging findings, surgical considerations, and outcome. J Neurosurg Spine. 2011;14(4):520-528. PMID: 21314281.
Haleem S, Adlan A, Azzopardi C, Botchu R. Calcified Thoracic Disc – A descriptive classification with clinical and management implications. J Craniovertebr Junction Spine. 2024;15(2). PMC11216641.
Yuan L, Chen Z, Liu Z, Li W, Sun C, Liu X. Clinical and radiographic features of adult calcified thoracic disc herniation: a retrospective analysis of 31 cases. Eur Spine J. 2023;32(7):2387-2395. PMID: 37222802.
Diehn FE, Maus TP, Morris JM, et al. Uncommon Manifestations of Intervertebral Disk Pathologic Conditions. RadioGraphics. 2016;36(3):801-823. PMID: 27082664.
Yue B, Chen B, Zou YW, et al. Thoracic intervertebral disc calcification and herniation in adults: a report of two cases. Eur Spine J. 2016;25(Suppl 1):118-122. PMID: 26329651.
Radiopaedia. Thoracic disc herniation. https://radiopaedia.org/articles/thoracic-disc-herniation