The unique anatomy of the thoracic spine means that stenosis is a fairly rare occurrence in comparison to cervical spinal stenosis or lumbar spinal stenosis. The thoracic spine is fused to the ribs and sternum, making it much more rigid and subject to less trauma from movement than these other spinal regions. Around 1% of spinal stenosis cases involve thoracic spinal stenosis. Having said that, the thoracic spine is actually much narrower than either the cervical or lumbar sections of the spine with and average diameter of around 12-14mm (the lumbar spinal canal can be 15-27mm). Any obstruction that does occur in this area has, therefore, a higher chance of impacting on the spinal nerves or the spinal cord itself.
Congenital Spinal Stenosis
Those with a congenitally narrow thoracic spinal canal are also liable to suffer spinal cord compression from relatively minor trauma to the spine. Inflammation, vertebral fracture, osteophyte (bone spur) growth, or disc herniation can occur, along with synovial cysts, and ligament calcification, all of which reduce the space available for the spinal nerves to travel through and the spinal cord itself.
Thoracic spinal stenosis may remain asymptomatic for many years until a patient begins to experience mild middle back pain. As the condition develops there may be pain in the lower back, down the legs, and a progressive loss of bowel and bladder control. In some cases the ability to walk may be affected, and muscle weakness and atrophy, along with paralysis can occur.
Thoracic Spinal Stenosis Diagnosis
As thoracic spinal stenosis is relatively rare, there is no clear-cut diagnostic procedure for the condition meaning that a differential diagnosis, or no diagnosis, may prevent early treatment of the pathology. Related conditions include Paget’s Disease, rheumatoid arthritis of the spine, spondylodiscitis, achondroplasia, and osteogenesis imperfecta. Physicians will usually be able to detect pathology of the thoracic spine more easily using myelograms rather than an MRI or CAT scan as the technique utilises contrast dye in order to visualize the bones of the spine more effectively.
Thoracic Spinal Stenosis Treatment
Treatment of thoracic spinal stenosis is usually conservative, involving the use of NSAIDs, and other analgesic and anti-inflammatory medications, physical therapy, steroid injections, and, occasionally, complementary therapies such as acupuncture. For patients experiencing severe, debilitating, symptoms such as extreme pain, incontinence, paralysis, numbness, and weakness, surgery may be advised in order to decompress the spine.
Surgical options may include laminectomy to remove a portion of the back bone and allow the spinal cord to be decompressed, or corpectomy to remove a body of tissue causing decompression of the spinal nerves and cord. Discectomy, laminotomy, laminoplasty, or foraminotomy, may all help relieve symptoms, and can, on occasion, be performed as minimally invasive back surgery procedures thereby reducing recovery time and the extent of tissue trauma. Spinal fusion may be appropriate in some circumstances in order to restore the rigidity of the thoracic spine and prevent excessive flexion or extension. Problems in the thoracic spine can have consequences for both lumbar and cervical spinal sections as extra pressure may be put on their structures to compensate for thoracic instability. An overview of the whole spine is, therefore, important in assessing the likely impact of any invasive treatment options.