What is Spinal Instability?
Spinal instability happens when the spine does not respond appropriately when faced with physiological loads. Instead of managing the load correctly, the spine moves in ways that cause irritation or pinching of the nerve roots. This instability can also lead to a great amount of pressure on the facet joints, causing inflammation. This can cause the paraspinal muscles to spasm, which can sometimes lead to the back locking up. If the instability is continuous, it can result in faster degeneration of the area of the spine and become a major source of pain.
What can cause Spinal Instability?
Certain events can occur in the process that leads to spinal instability. Vertebral discs serve as shock absorbers and manage the flexibility and motion of each spinal segment. When the vertebral discs become herniated or degenerative, they lose their tension, which can make them bulge and increase movement between each vertebrae. In addition, degenerative discs can lose height, which can cause the facet joints to become displaced and move out of their correct alignment. This can lead to arthritis overgrowth of the joints and create bone spurs, which limit movement and cause pain. One can experience pain through extension or flexion and the vertebrae move abnormally. This type of movement irritates the nerve and causes leg or back pain.
Conditions that contribute to spinal instability include:
- Degenerative Disc Disease
- Weak spine caused by infection or tumor
- Spine Fractures
How is Lumbar Instability Treated?
The goal of a spinal fusion procedure is to eliminate or reduce pain caused by joints that have worn out over a period of time. In this procedure, two bones separated by a joint are joined together to grow into one bone. To accomplish this, surgeons use a bone graft, which is normally taken from the patient’s pelvic area or a bone bank. There are several different approaches to this kind of spine surgery. Your spine doctor will determine which option is best for you based on your set of symptoms.
All of these surgical options are designed to prevent motion at the vertebral segment. Some of the surgical approaches include:
Anterior approach: This approach allows the spine surgeon to remove the intervertebral disc from the front and place a bone graft between the vertebrae. An incision is made in the abdominal area above the pelvic bone. The abdominal organs are carefully moved to the side which allows the surgeon to see the front part of the spine. Once the problem disc is located it is surgically removed and bone graft is placed.
Posterior approach: An incision is made in the back of the patient. In this surgery the vertebrae can either be fused or the disc is removed. If the disc is removed, it is replaced with bone graft. The incision is made in the middle lower area of the back, at the location of the spine where it will be fused together. The benefit of this approach allows the surgeon to see areas of pressure and what is causing them, whether it is a bulging disc, thickened ligaments, or a bone spur. After removing whatever is causing the pressure, the spinal fusion is performed with a bone graft.
Combined approach: Because their are certain limitations of just performing surgery from the anterior or posterior approach, and not getting the full scope of what the patient needs to improve their symptoms, some spine surgeons will sometimes make an incision from the front and from the back.
After the procedure
If the surgery is successful, the vertebrae will need three months to completely fuse together, and will continue to fuse and grow for the next year. A patient may be required to wear a brace to ensure complete stability and spinal fusion, depending on the location of your surgery. Your spine surgeon will put a post-surgical physical therapy program in place to improve mobility and strength. This rehabilitation will help you return to daily activities as soon as possible. Physical therapy promotes the flexibility and strength of your spine.