Problems of the Thoracic Spine
The height of the disc maintains the separation distance between the adjacent bony vertebral bodies. This allows motion between the vertebrae to occur, with the cumulative effect of each spinal segment yielding the total range of motion of the spine in any of several directions. Proper spacing is also important because it allows the intervertebral foramen (the opening the nerve must pass through) to maintain its size, which allows the individual nerve roots room to exit without being compressed or "pinched."
Shock absorption allows the spine to compress and rebound when the spine is stressed during such activities as jumping and running. Importantly, it also resists the downward pull of gravity on the head and trunk during prolonged sitting and standing.
The elasticity of the disc allows "motion coupling" so the spinal segment may flex, rotate and bend to the side all at the same time during a particular activity. This would be impossible if each spinal segment were locked into a single axis of motion.
The jelly-like central portion of the disc is called the Nucleus Pulposus. It is composed of 80% to 90% water. The solid portion of the nucleus is a very special type of connective tissue.
The outer ligamentous ring around the Nucleus Pulposus is called the Annulus Fibrosus, which completely seals the nucleus, and allows pressure inside the disc to rise as the disc is loaded. The annulus has overlapping radial bands, not unlike the plies of a radial tire, and this allows forces to be handled by the annulus without rupture under normal stress.
The disc functions as a hydraulic cylinder. The annulus interacts with the nucleus. As the nucleus is pressurized, the annular fibers serve a containment function to prevent the nucleus from bulging or "herniating." The gelatinous nuclear material directs the forces outward, and the hoops of annular fibers help distribute that force without injury.
Pain Caused by the Disc
Thoracic disc disease can cause pain and other symptoms in two ways:
1. Herniated disc
If the annular fibers stretch or rupture, allowing the pressurized nuclear material to bulge or herniate and compress nerves, arm and shoulder pain and weakness may result. This is the condition called a pinched nerve, slipped disc or herniated disc. This condition will typically cause radiating arm pain as a result of the irritation against the nerve root.
The overwhelming majority of patients with a herniated cervical disc heal without surgery. If surgery is indicated, it involves removal of the portion of herniated disc material, such as a discectomy or microdiscectomy.
2. Degenerative disc disease
Improper movement over time as well as trauma from an accident can also cause disc degeneration and pain. For example, the disc may be damaged as the result of some trauma that overloads the disc, and portions of the annular fibers may tear. These torn fibers can then cause an inflammatory response when they are subjected to increased stress, and may cause pain, directly or indirectly, by muscle spasms as the neck muscles try to compensate. When there is compression of the spinal cord, caused by arthritis, bone spurs or narrowing of the spinal canal, a condition called cervical spondylotic myelopathy (CSM) can occur.
Spondylolisthesis is the condition when the vertebrae are displaced either forward or backward on the vertebra below it.
- Scoliosis is the lateral curvature either right or left of the spine that can involve one or more levels and can include both directions called an "S" Curve.
- Kyphosis is the abnormal bowing of the back usually the upper back.
- Radiculopathy, sometimes called radiculitis refers to any disease of the nerve root and usually involves inflammation.
- Compression fracture is usually an osteoporatic condition and may or may not involve trauma.
A thoracic myelogram is a test in which the radiologist places X-ray contrast (X-ray dye) into the fluid-filled sac that surrounds the lower thoracic nerve roots.
For a thoracic myelogram, you will be placed on your stomach on the X-ray table with a rolled-up blanket or pillow under your mid-section to produce a gentle curve in your back. This helps to spread the backbones apart. Your skin is then cleansed and anesthetized. A very thin needle is placed between the backbones until the tip of the needle is in the fluid-filled space that surrounds the spinal nerves. Approximately 10 to 12 ccs of X-ray contrast is introduced through the needle. X-ray films are then obtained.
Following the myelogram, you will go to the CT Scan Room for additional X-ray pictures.
The entire procedure takes approximately one hour, with one-half hour in each room. After the CT myelogram, you will be brought back to your chair. An additional hour of recovery in this department is advised to allow for rest, initiation of fluids and explanation of your discharge instructions.
When you go home you are to stay on complete bed rest for a full 24 hours after the myelogram. You are encouraged to drink fluids in excess. By following these instructions, you will help to prevent the most common adverse effect of a myelogram, which is the possibility of a headache.
A post-myelogram headache can occur when the small puncture hole in the fluid-filled sac does not heal, and allows for the leakage of spinal fluid out of the hole. Bed rest will help the small puncture hole to close, and the excess fluids will allow your body to keep up with the loss of the small amount of spinal fluid that may leak out of the hole.
Conservative Treatment Options
Conservative treatment options for your cervical, thoracic and/or lumbar spine may include one or all of the following:
Body braces for the spine
When conservative treatments fail to help your spinal condition, a surgical consultation is recommended to determine what surgical options are available.
Understanding Thoracic Laminectomy
The operation is done while the patient is lying on his or her abdomen, or on the side. A small incision is made in the lower back. The surgeon then uses instruments to pull aside the fat and muscle, revealing the lamina portion of the vertebrae. The portion of the lamina is removed to expose the compressed nerve root. The source of the pressure varies, and can be relieved by removing part of a herniated disc, a disc fragment, or a rough bony growth, often called a bone spur. Once the cause of this pressure is removed, the nerve or nerves can begin to heal. It is normal to have discomfort after the surgery, especially in the lower back. It is important to note that this DOES NOT mean the operation was unsuccessful or that your recovery will be delayed. It is also not uncommon to experience leg aching, as it takes time for the previously compressed nerve to heal and for localized swelling to fade. Muscle spasms in the back and even down the legs can also occur, and medications will be given to help control pain and relieve spasms.
Understanding Thoracic Fusion
The surgical procedure referred to as spinal fusion is usually to treat pain caused by motion between two affected vertebrae. The surgical treatment for this pain usually involved eliminating the motion between affected vertebrae by removing all or most of the disc and replacing it with a bone graft, or an instrumentation device such as metal plates or a metal cylindrical cage.
The bone graft can be obtained from the hip area (iliac crest) or a bone bank. New devices are on the horizon such as bone morphogenic protein-7 (BMP-7).
Your surgeon may discuss this and other options with you. Sometimes a thoracic fusion surgery will include a procedure called a thoracotomy, which is removing part or all of a rib, entering the chest cavity and exposing the thoracic spine.