The lumbar spine is the lower portion of the spine found at the center of the curve of the low back. This area can be a common source of pain. Low back pain is the second most common reason for visits to the family physician, behind only the common cold. As people become older, various changes occur in the lumbar spine that can cause pain. In most cases these changes are normal degenerative arthritis (wear of cartilage over time). The physician must also rule out other more serious conditions including tumor, infection, or fracture.

Fortunately, more than 90% of patients with low back pain will have improvement in their symptoms regardless of treatment within six weeks. During that time the physician has various treatment options including medications, physical therapy, or injections that can help ease the symptoms. Some of those patients that do not improve during the first six weeks may be candidates for surgery. The spine surgeon has different types of surgical options available based on the specific cause of pain.

Lumbar Fusion Candidates

Lumbar fusion surgery may be indicated for a variety of lumbar spine problems. Generally, lumbar spine problems are first treated conservatively. Then, if low back pain, numbness, tingling or weakness in the legs does not improve, some individuals may be candidates for lumbar spine fusion surgery.

The most common reason for surgery is leg pain or sciatica. This pain may be the result of a herniated lumber disc causing pressure on one or more of the spinal nerves. Leg pain may also be caused by abnormal motion of the vertebrae.

Spondylolisthesis

In this condition one vertebra has slipped forward over another. If the vertebra continues to slip back and forth, the spinal nerves may be affected, causing leg pain, numbness, tingling and/or weakness. A spinal fusion may be recommended to stop this abnormal motion.

Normal and Developmental Defect

Low back pain caused by spondylolisthesis, in which one vertebra slips forward on another, may be due to a development defect or fracture.

Degenerative Disc Disease

In degenerative disc disease, the discs or cushion pads between your vertebrae shrink, which can cause abnormal motion and possibly an unstable area in your spine. As a result, the vertebrae may compress the spinal nerves, leading to leg pain.

Arthritis

Severe arthritis of the spine is called spinal stenosis. As the body ages, wom vertebrae and discs may develop bony spurs, which may cause stenosis, or narrowing of the openings for the spinal cord and nerves. These spurs irritate the spinal nerve roots and cause pain, numbness, tingling or weakness down the legs. Sometimes this condition requires lumbar fusion surgery to stabilize the spine, and prevent abnormal motion after pressure on the spinal nerves is removed.

Lumbar Fusion Alternatives

Ankle replacement options include smoothing the surfaces where the bones meet (debridement), fusing the bones of the ankle joint, removing bone and procedures aimed at restoring the bone and cartilage of the ankle.

Patients with concomitant subtalar joint arthritis (who would require a tibiotalarcalcaneal fusion) or contralateral ankle arthritis or fusion (who may end up with bilateral ankle fusions) are ideal candidates for total ankle arthroplasty, as the morbidity of the fusion alternatives is significantly higher than an isolated ankle fusion.

The best approach will depend on the patient, the patient's lifestyle and the condition of the joint.

Intradiscal Electrothermal Coagulation (IDET)

Intradiscal electrothermal coagulation, or annuloplasty, involves inserting a needle into the lumbar disc space, passing a catheter through the needle, and heating up the annulus (the outer core of the disc space). The exact mechanism by which the procedure relieves pain has not been clearly established, but it is theorized that the heat contracts and thickens collagen fibers in the disc wall, which in turn seals up painful tears and cracks and reduces pain. The procedure also cauterizes nerve endings which is thought to make them less sensitive. Not all patients benefit from IDET, and the treatment is more likely to help people with less severe degenerative disc disease than people with significant disc degeneration. IDET is minimally invasive and usually done on an outpatient basis (no overnight hospital stay) under mild sedation and a local anesthetic. Although the procedure is minimally invasive it has largely fallen out of favor in the spine world as it has marginal clinical efficacy. Most insurance companies no longer cover the procedure.

Artificial Discs Replacement

Disc replacement surgery involves replacing the painful disc in the spine with an artificial disc. As of August 2006, two brands of lumbar artificial disc are available for use in patients in the U.S.: the Charite lumbar artificial disc and the PRODISC-L lumbar artificial disc. A number of other artificial disc brands are in the clinical trial testing phase. The goal of artificial disc replacement surgery is to preserve the normal motion of the spine (unlike fusion, which eliminates motion at the painful spinal segment). Artificial disc surgery has two primary theoretical advantages over spinal fusion; 1) it is thought that preserving spinal motion reduces the risk that other segments of the lumbar spine will wear down prematurely; 2) it is believed that artificial disc surgery may achieve better pain reduction than fusion. However, these potential benefits come at the expense of greater risk with the surgery. Any motion preservation device can fail by extrusion or wearing out with time. Revision surgeries are expensive and extremely dangerous. The risk/benefit ratio of artificial disc vs fusion is still largely unknown, and currently many insurance companies are not covering the procedure.

Posterior Dynamic Stabilization

This treatment is different from fusion in that posterior dynamic stabilization seeks to preserve motion in the spine while also taking pressure off the diseased vertebral disc. The theory is that removing pressure from the painful disc will create a favorable healing environment and reduce pain. The devices used in the surgery are designed to unload pressure from the vertebral disc in the same way a dynamic (moveable) brace unloads pressure from an injured knee or ankle to allow it to heal. Various forms of posterior dynamic stabilization devices are still in the investigative or testing phase or early in use, and their efficacy and potential risks and complications have not yet stood the test of time.

Disc Regeneration

Researchers in cellular and molecular biology are exploring ways to use gene therapy to stimulate regeneration of the vertebral disc and/or to slow or prevent degeneration of the disc. The hope is that this therapy could prevent the need for surgery. For example, in animal studies, the BMP-12 gene (bone morphogenetic protein) has dramatically increased the generation of cells in both the nucleus and the annulus of the vertebral disc. BMP-12 is a molecule that, among other duties, promotes formation of embryonic joints. Research is also being performed on gene therapy that could inhibit the degeneration process. Gene therapy for treatment of the intervertebral disc is still in the early stages of research.

Lumbar Fusion Outcome & Benifits

The goal of lumbar fusion surgery is to relieve pain, numbness, tingling and weakness, restore nerve function and stop or prevent abnormal motion in the spine. This is done by fusing the vertebrae together. The lumbar fusion can be done in the front or the back of the spine.

If the fusion is performed in the front of your spine, the surgeon will remove the disc (cushion between vertebrae) and any arthritic areas, and place a bone graft between the vertebrae where it eventually fuses to the surrounding vertebrae to stop abnormal motion. If the fusion is performed in the back of your spine, a bone graft will be placed on the sides of the vertebrae where it will grow together to the vertebrae to stop abnormal motion.

The bone graft may be one of two types: an autograft (bone taken from your own body usually your pelvis) or an allograft (bone from a bone bank). Sometimes metal rods, screws or hooks are also used with the bone graft to further stabilize the spine. This is referred to as "instrumentation."

When the vertebrae have been surgically stabilized, abnormal motion is stopped and function is restored to the spinal nerves.

Prepare for Lumbar Fusion

Once the decision to proceed with surgery is made, there are several things that may need to be done. Your foot and ankle surgeon may suggest a complete physical examination by your medical or family doctor. This is to ensure that you are in the best possible condition to undergo the operation. You may also need to spend time with the physical therapist who will be managing your rehabilitation after the surgery.

On occasion a therapist will begin the teaching process before the surgery to ensure that you are ready for the rehabilitation afterwards. This includes measurements of your current pain levels, functional abilities, and the available movement and strength of each ankle. A second purpose of the preoperative visit is to prepare you for your upcoming surgery. You’ll begin to practice using crutches since you will need to use these for several weeks after surgery.

Finally, an assessment will be made of any needs you’ll have at home once you’re released from the hospital. On the day of your surgery, you will probably be admitted to the hospital early in the morning. You will be instructed not to eat or drink anything after midnight the night before surgery.

You should plan on being in the hospital for one to two nights following surgery. How long depends on your progress with physical therapy, how much discomfort you are in, your ability to get out of bed, and success using crutches or a walker. To perform an ankle replacement, you may be placed under general anesthesia, regional anesthesia, or you may have a spinal type anesthetic.

Lumbar Fusion Surgery Overview

At each level in the spine, there is a disc space in the front and paired facet joints in the back. Working together, these structures define a motion segment and permit multiple degrees of motion. Two vertebral segments need to be fused together to stop the motion at one segment, so that an L4-L5 (lumbar segment 4 and lumbar segment 5) spinal fusion is actually a one-level spinal fusion.

A spine fusion surgery involves using bone graft to cause two vertebral bodies to grow together into one long bone. Bone graft can be taken from the patient's hip (autograft bone) during the spine fusion surgery, harvested from cadaver bone (allograft bone) or manufactured (synthetic bone graft substitute).

In general, a lumbar spinal fusion surgery is most effective for those conditions involving only one vertebral segment. Most patients will not notice any limitation in motion after a one-level spine fusion. Only in rare cases should a three (or more) level fusion surgery for pain alone be considered, although it may be necessary in cases of scoliosis and lumbar deformity.

When necessary, fusing two segments of the spine may be a reasonable option for treatment of pain. However, spinal fusion of more than two segments is unlikely to provide pain relief because it removes too much of the normal motion in the lower back and places too much stress across the remaining joints.

There are several types of spinal fusion surgery options, including:

• Posterolateral gutter fusion: The procedure is done through the back
• Posterior lumbar interbody fusion (PLIF/TLIF): The procedure is done from the back and includes removing the disc between two vertebrae and inserting bone into the space created between the two vertebral bodies
• Anterior lumbar interbody fusion (ALIF): The procedure is done from the front and includes removing the disc between two vertebrae and inserting bone into the space created between the two vertebral bodies
• Anterior/posterior spinal fusion: The procedure is done from the front and the back

Lumbar Fusion Recovery

Patients may be placed in a rigid body brace after surgery. This brace may not be needed if the surgeon attached metal hardware to the spine during the surgery. The drain tube is removed from the wound within 24 to 48 hours.

Patients usually stay in the hospital after surgery for up to one week. During this time, a physical therapist helps patients learn safe ways to move, dress, and do activities without putting extra strain on the back. Patients may be instructed to use a walker for the first day or two. Before going home, patients are shown how to help control pain and avoid problems.

Patients are able to return home when their medical condition is stable. However, they are usually required to keep their activities to a minimum in order to give the graft time to heal. Patients should avoid bending, lifting, twisting, driving, and prolonged sitting for up to six weeks. Outpatient physical therapy usually starts a minimum of six weeks after surgery.

Patients gradually do more activities and exercise with the goal of getting back to a normal and productive life.

Lumbar Fusion After Care

Rehabilitation after posterior lumbar fusion can be a slow process. Many surgeons prescribe outpatient physical therapy beginning a minimum of six weeks after surgery. This delay is needed to make sure the fusion is taking. You will probably need to attend therapy sessions for two to three months. You should expect full recovery to take up to eight months. Therapy can usually progress faster in patients who had an instrumented fusion.

At first, treatments help control pain and inflammation. Ice and electrical stimulation treatments are commonly used to help with these goals. Your therapist may also use massage and other hands-on techniques to ease muscle spasm and pain.

Active treatments are slowly added. These include exercises for improving heart and lung function. Short, slow walks are generally safe to start with after posterior lumbar fusion. Swimming and use of a stair-climbing machine are helpful in the later phases of treatment. Therapists also teach patients specific exercises to help tone and control the muscles that stabilize the low back.

Your therapist also works with you on how to move and do activities. This form of treatment, called body mechanics, is used to help you develop new movement habits. This training helps you keep your back in safe positions as you go about your work and daily activities. Training includes positions you use when sitting, lying, standing, and walking. You'll also work on safe body mechanics for lifting, carrying, pushing, and pulling.

As your condition improves, the therapist tailors your program to help prepare you to go back to work. Some patients are not able to go back to a previous job that requires strenuous tasks. Your therapist may suggest changes in job tasks that enable you to go back to your previous job or to do alternate forms of work. You'll learn to do these tasks in new ways that keep your back safe and free of strain.

Before your therapy sessions end, your therapist will teach you how to avoid future problems.

Lumbar Fusion Possible Risks

As with any operation, there are risks involved with spine fusion surgery. Some patients may develop a distended abdomen and may not be able to eat. If this happens, a special tube may be inserted to relieve the distension.

Another complication is a wound infection. Antibiotics are given before and after the operation to prevent this from occurring.

Urinary problems after spine surgery may include urinary retention and urinary tract infection. A catheter will be placed into your bladder at the time of surgery and will be removed as soon as possible when you are up and around.

Some patients may continue to have pain at the bone graft donor site. If the fusion does not heal, (a condition known as pseudoarthrosis) the instrumentation, such as rods, screws, hooks may break, and further surgery may be required. People who smoke are at a higher risk for pseudoarthrosis complications.

Other complications include phlebitis in your legs and blood clots in your lung. To protect against these problems, you will wear compression boots on your calves during and after surgery.

Rare complications include a failure to improve, worsening neurological symptoms, paralysis and possibly death. Your doctor will discuss these potential risks with you before asking you to sign a consent form.

Lumbar Fusion Revision

Revision surgery often involves correcting a deformity caused by a previously failed back surgery, breakage of instrumentation or pseudoarthrosis. The type of revision depends on the problem. The procedure may include operating on both the front and back of the spine. The incidence of complications from revision lumbar spine fusion surgery is higher than in first-time procedures. It is also more difficult to relieve pain and restore nerve function in revision surgery. Patients should be aware that the chance of having long-term spinal pain is increased.