Herniated Disc Disease
The inter-vertebral discs are the shock-absorbing cushions between each pair of vertebrae in your spine. Each disc has a strong outer ring of fibers, called the annulus, and a soft, gelatinous center, called the nucleus pulposus. The disc’s nucleus serves as the main shock absorber for the adjacent vertebrae.
When a tear occurs in the outer (annular) ring of the disc, the soft nucleus pulposus can protrude into the spinal canal. This common and painful disorder is called a herniated disc (also known as a ruptured disc or a prolapsed disc). The protrusion of the nucleus pulposus can press on a nerve root or the spinal cord. The damaged disc can also leak fluid, which may inflame nerve roots. For this reason, herniated discs can become extremely painful.
When a herniated disc occurs in the mid back it can be extremely serious. The smaller spinal canal in the thoracic (mid back) region leaves very little space around the spinal cord. In severe cases, the pressure of a herniated disc on the thoracic spinal cord can lead to paralysis below the waist. Fortunately, herniated discs much more commonly occur in the lumbar or cervical spine, where the spinal canal is larger.
In addition to back pain, a herniated disc can cause pain in other parts of the body. Because nerve roots carry signals to other parts of the body, a herniated disc that compresses a nerve root can cause pain in other body parts. For example, a herniated disc in the lower back may compress the sciatic nerve root, causing the pain and/or numbness known as sciatica, which runs down the back of the leg. A herniated cervical disc, on the other hand, can cause neck and arm pain. In fact, the hallmark of a herniated disc is radicular pain—pain that runs down into the arm or leg. This pain also may be associated with numbness or weakness in the same distribution.
Regular wear and tear, degeneration or trauma can all cause a herniated disc. Like muscles and ligaments, discs heal from a tear by forming scar tissue, which is weaker than normal tissue.
A traumatic event can put too much pressure on a disc all at once, causing a sudden rupture. For example, falling from a ladder and landing in a sitting position applies a tremendous amount of sudden force on the spine, which can result in a broken vertebra or a ruptured disc. A smaller amount of force can also rupture a disc, especially if the tough outer ring (annulus) has been weakened by repeated injuries that have added up over time. A weakened disc may rupture while lifting or bending, low-impact activities that probably would not have caused a problem five years earlier. The effects of aging on the spine, which makes discs more vulnerable to ruptures, is the most common cause of disc herniation in the thoracic spine.
To diagnose a herniated disc, the doctor will begin by obtaining a complete history of the problem and administering a physical exam. An MRI, the most common test used to diagnose a herniated disc, is painless and accurate.
The treatment of a herniated disc depends on the symptoms. Since most herniated discs heal without surgical treatment, your doctor may first suggest careful monitoring. If the symptoms improve, no other treatment may be needed. However, if symptoms worsen, your doctor might suggest surgery.
Your doctor may prescribe rest and observation to monitor the progression of the problem. Depending on the amount of pain, medications and/or physical therapy may be prescribed. If you have severe pain from nerve root irritation, your doctor may prescribe an epidural steroid injection (ESI). Unfortunately, this treatment succeeds in reducing the pain from a herniated disc in only about half of all cases.
The traditional surgical treatment for a herniated disc is a combination of laminotomy and discectomy. In a laminotomy, an opening is made in the lamina (covering of the disc) to relieve pressure on the affected spinal nerves; a discectomy removes the herniated disc. Microdiscectomy achieves the same results as traditional discectomy, but uses a less invasive technique, enabling a faster recovery for the patient. Endoscopic Discectomy is an even newer, more technologically advanced version of the microdiscectomy. The specific nature of the herniated disc will determine what the best procedure will be.