The twelve thoracic intervertebral discs connect adjacent vertebral bodies from T1-T2 to T12-L1, each consisting of a central nucleus pulposus and a surrounding annulus fibrosus. Thoracic discs are proportionally thinner than cervical or lumbar discs relative to vertebral body height, limiting thoracic mobility. The kyphotic thoracic curvature and costovertebral joints further restrict motion at each level.
Thoracic disc herniation is far less common than cervical or lumbar, accounting for fewer than 1% of all disc herniations. The thoracic spinal canal is narrow relative to the spinal cord, meaning even small herniations can cause myelopathy. Calcified thoracic disc herniations are a specific entity requiring surgical approach planning. Anterior thoracoscopic, lateral extracavitary, and posterior laminectomy approaches each have specific indications. Scheuermann kyphosis involves multiple thoracic disc and end-plate abnormalities.
Posterior or posterolateral disc material displacement in the thoracic spine can produce thoracic myelopathy with lower limb spasticity, sensory level, and bladder dysfunction, or thoracic radiculopathy with dermatomal chest or abdominal pain, requiring MRI for diagnosis and surgical decompression when neurological deficits are present.
A developmental condition of multiple thoracic disc and end-plate irregularities producing structural kyphosis greater than 45 degrees with characteristic anterior vertebral body wedging, managed with physiotherapy, bracing in growing adolescents, or surgical correction for severe curves.
