Lumbar Spinal Fusion Surgery
Stopping the pain caused by joints in the spine that have worn out constitutes the main goal of an operation on the skeletal system. Fusing joints together in the spine reduced pain from degeneration. Specifically, a Lumbar Spinal Fusion Surgery fuses two bones, usually separated by a joint, together into one bone. To clarify, the medical term for this type of fusion procedure refers to arthrodesis.
For your information, spinal fusion has been used for many years to treat painful conditions in the lumbar spine. Over the past decade, dramatic improvements have been implemented in the way that spinal fusion operations are performed. In addition, one major improvement has been the development of fixation devices.
In order to understand your symptoms and treatment choices, patients should understand the anatomy of the lower back. Also, this includes becoming familiar with the various parts that make up the lumbar spine and how these parts work together.
Learn more about the anatomy of the lumbar spine.
When does Lumbar Spinal Fusion Become Necessary?
Only when all other conservative treatments have failed will your doctor suggest fusion surgery. To clarify, the following back conditions may require a spinal fusion, including:
- degenerative disc disease
- spinal instability
- spine curvature
- spondylolysis and spondylolisthesis
By permanently connecting two or more vertebrae (spinal fusion) in your spine and eliminating motion between them, scoliosis and other types of spine conditions can get corrected. Spinal fusion surgery is a complex and intricate procedure; hence, the length of the surgery will vary by patient
Degenerative Disc Disease
Degeneration of the discs between one or more vertebrae may require a spinal fusion of the vertebrae on both sides of the degenerative disc. The intervertebral discs look like flat, round “cushions” that act as shock absorbers between each vertebra in the spine. The disc allows motion to occur between each vertebra. Removing a degenerated disc and allowing the two vertebrae to fuse together can reduce pain.
Each spinal segment is like a well-tuned part of a machine. All of the parts should work together to allow weight-bearing, movement, and support. When one segment deteriorates to the point of instability, it can lead to localized pain and difficulties. Segmental instability occurs when there is too much movement between two vertebrae. To clarify, the excess movement of the vertebrae can cause pinching or irritation of nerve roots. Also, it can also cause too much pressure on the facet joints, leading to inflammation. To further explain, it can cause muscle spasms as the paraspinal muscles try to stop the spinal segment from moving too much. The instability eventually results in faster degeneration in this area of the spine.
Surgeons use lumbar fusion for scoliosis and kyphosis — where the spine has an abnormal curve. These spine deformities may result from congenital or degenerative spine conditions. A lumbar fusion can stabilize the spine and correct the problem.
Spondylolysis and Spondylolisthesis
Spondylolisthesis, the term used to describe when one vertebra slips forward on the one below it, usually occurs when a spondylolysis (defect) exists in the vertebra on top. There two main parts of the spine that keep each vertebra aligned to the disc and the facet joints. When spondylolisthesis occurs, the facet joint can no longer hold the vertebra back. The intervertebral disc may slowly stretch under the increased stress and allow the upper vertebra to slide forward. A surgeon may use fusion for both conditions to stop motion in the problem vertebrae.
Lumbar Spinal Fusion Surgery
During a spinal fusion, a bone graft joins two or more vertebrae. The vertebrae grow together during the healing process, creating a solid piece of bone. The bone graft helps the vertebrae heal together, or fuse. A bone from the pelvis can serve as a bone graft at the time of surgery. However, some surgeons prefer to use a bone graft from a bone bank (called allograft).
Your surgeon can use an anterior (from the front) approach, a posterior (from the back) approach, or a combined approach to lumbar fusion surgery.
In some cases, it may be best to consider placing the bone graft between the vertebral bodies. The anterior interbody approach allows the surgeon to remove the intervertebral disc from the front and place the bone graft between the vertebrae.
This operation begins by making an incision in the abdomen, just above the pelvic bone. The organs in the abdomen, such as the intestines, kidneys, and blood vessels, are moved to the side to allow the surgeon to see the front of the spine. The surgeon then locates the problem disc and removes it. The bone graft becomes placed into the area between the vertebrae where the disc has been removed.
The posterior approach begins from the back of the patient. This approach can fuze the vertebral bones or it can include removal of the problem disc. When the doctor removes a disc, a bone graft will replace it. Then the surgeon moves the spinal nerves to one side and inserts the bone graft between the vertebral bodies. This is called a posterior lumbar interbody fusion. With a posterior approach, an incision starts in the middle of the lower back over the area of the spinal fusion area. The surgeon moves the muscles to the side so that the surgeon can see the back surface of the vertebrae.
Once the spine is visible, the lamina of the vertebra gets removed to take the pressure off the dura and nerve roots. This allows the surgeon to see areas of pressure on the nerve roots caused by bone spurs, a bulging disc, or a thickening of the ligaments. The surgeon can remove or trim these structures to relieve the pressure on the nerves. Once the surgeon sees that all pressure has been removed from the nerves, a fusion can proceed. When operating from the backside of the spine, the most common method of performing a spinal fusion occurs when the surgeon places strips of bone graft over the back surface of the vertebrae.
Working between the vertebrae from the back of the patient has limitations. Because of the fact that the spinal nerves are constantly in the way, the surgeon needs to proceed carefully. The movement of these nerves is limited. This limits the ability to see the area and doctors do not have much room to use instruments and place implants. For these reasons, many surgeons prefer to make a separate incision in the abdomen and actually perform two operations — one from the front of the spine and one from the back. The two operations occur at the same time, but they may happen done several days apart.
In the past, spinal fusions of the lumbar spine were performed without any internal fixation. The surgeon simply roughed up the bone, placed bone graft material around the vertebrae, and hoped the bones would fuse. Sometimes, patients were placed in a body cast to try to hold the vertebrae still while healing. The patient was lucky to have a 70 percent chance of successful fusion.
Spine surgery requires special knowledge, skills and abilities to perform it well. The vertebrae are small, and there is not much room to place small instruments. Also, many nerves can get in the way of putting screws into the vertebral body. With the lower back sometimes getting a large amount of stress, finding a metal device capable to hold the bones together can be difficult. However, over the past two decades, some very inventive devices have changed the way surgeons perform spinal fusions.
Pedicle Screws and Rods
The surgeon may use some type of metal screws, plates, and rods to hold the vertebrae in place while the spine fusion heals. Designed to stabilize and hold the bones together while the fusion heals, these devices have greatly improved the success rate of fusion in the lower back.
A new type of device called an intervertebral fusion cage can assist in a spinal fusion between two or more vertebrae. These implants spread the two vertebrae apart while the fusion heals.
Like all surgical procedures, operations on the spine may have complications. Because the surgeon operates around the spinal cord and nerves, back operations are always considered extremely delicate and potentially dangerous. Patients should take the time to review the risks associated with spine surgery with their doctor. Make sure you agree with both the risks and the benefits of the procedure planned for your treatment.
Lumbar Spinal Fusions Surgery Recovery
The bones take a minimum of three months to fuse together and become solid. Yet the bone graft will continue to mature for one to two years. Your doctor may have you wear a rigid brace for up to three months to keep your spine still and make sure the bones fuse. You may not require a rigid brace after fusion with instrumentation.
Most patients return home when their medical condition stabilizes, usually within one week after fusion surgery. Limit your activities to avoid doing too much too soon. Avoid bending, lifting, twisting, and driving for at least six weeks.
Your doctor may have you attend physical therapy beginning a minimum of six weeks after surgery. A well-rounded rehabilitation program assists in calming pain and inflammation, improving your mobility and strength, and helping you do your daily activities with greater ease and ability. Therapy sessions may be scheduled up to three times each week for eight to 12 weeks.
The goals of physical therapy provide the following to the patient:
- learn ways to manage your condition and control symptoms
- improve flexibility and core strength
- learn correct posture and body movements to protect the fusion
- return to work safely
If you or a loved one suffers from spinal pain, you owe it to yourself to call Southwest Scoliosis and Spine Institute at 214-556-0555 to make an appointment.