Degenerative disc disease in the thoracic and lumbar vertebrae can be a painful condition. Scientists do not know the cause of this disease, but its result is that the intervertebral disc becomes mechanically unstable. This causes it to herniate from its intervertebral space and into the area occupied by the spinal cord or spinal nerve roots. The resultant pushing on these neural tissues creates pain and other symptoms, often requiring surgery to trim or even remove the disc.
Anatomy of the Disease
The intervertebral discs are essentially pads which separate the vertebrae. Each disc has a spongy inner region and a thick fibrous outer region. In disc degeneration, the inner portion becomes dehydrated and is less able to absorb shock. This more brittle state causes the outer region to form tears, and eventually the inner portion herniates, or pushes through the tear. It is this herniated disc that pushes into the space where spinal nerves or the spinal cord reside. Pressure on these tissues produces the unpleasant symptoms.
Risk Factors
The underlying cellular causes of degenerative disc disease are not known. But like all body parts, the intervertebral discs change with age. Factors such as normal wear and tear, vibrations, trauma, genetics and smoking all contribute to speeding up the degeneration process. As described by the Mayfield Clinic, these factors all combine in some way to cause intervertebral discs to deteriorate and lose mechanical strength.
Who is Afflicted
Advancing age is the most significant risk factor for thoracic disc degeneration, and it occurs equally in men and women. Symptomatic thoracic disc herniations are extremely rare, however. Individuals with spinal deformities such as kyphosis and scoliosis are at increased risk, as are those exposed to traumatic twisting and torsion. Also at higher risk are the elderly who have chronic illnesses such as osteoarthritis and osteoporosis.
Symptoms
Symptoms occur when the disc begins to protrude onto the neural tissues. According to MDGuidelines, symptoms of thoracic and lumbar degenerative disc disease include pain in the thoracic region of the back, buttocks, legs and feet, weakness in the lower extremity and lack of coordination. Bladder and bowel function may or may not be affected. It is not known why some people have pain while others with equal degrees of degeneration do not.
Treatment
When symptoms cause persistent neurological deficits, surgery is recommended to cut away the herniated portion or completely remove the disc, according to MDGuidelines. Discectomy can be performed from either the posterior or the anterior side of the body. When the disc is removed, fusion of the vertebrae above and below it can occur. This is more common in lumbar discectomies, because the lumbar vertebrae are very mobile bones. This surgery allows the vertebrae to fuse together, thereby minimizing the pathologies that result from two vertebrae rubbing against each other.
