What is spine fusion and why do I need it?
Back pain is common and affects about 80% of Americans at some time in life. It is usually caused by overuse, muscle strains, poor body mechanics or injury. Degenerative disc disease (DDD) affects up to 40% of all patients with low back pain and is generally caused by the conditions mentioned above and is related to aging and wear and tear on the back.
Your back is made up of bone vertebrae and cushioning discs and those discs can wear out, tear or rupture. When damage occurs, and the cushioning effect is lost, pressure is exerted on nerve roots. This can lead to nerve impingement, a cause of the inflammation and debilitating pain that is often associated with disc disease and may be the reason your Doctor recommended lumbar fusion. (See the animated lumbar spine illustration to the right.)
Initially, your doctor will recommend a conservative treatment approach. If a physician suspects a disc problem, a MRI or CT scan can be performed to evaluate disc damage. Pain medication, anti-inflammatory drugs, physical therapy and lifestyle changes usually are the first line of treatment. Once patients get past the immediate acute pain, they are expected to work on a long-term program of back exercises, stretching, and, in some cases, modification of their work environment to decrease back stress.
After more conservative options have been attempted without success, physicians may suggest surgical options. Back surgery carries a certain degree of risk because of the proximity to the spinal cord. And there’s always the possibility a surgical procedure, even one performed successfully, might not bring pain relief.
Lumbar spinal fusion is the most frequently performed of all spinal fusion operations. For many years the gold standard surgical treatment for degenerative disc disease has been spinal fusion. In a healthy spine, the cushioning disc allows motion to occur between each vertebra. Removing a degenerated disc and allowing the two vertebrae to fuse together can stabilize the area, restoring the spine to it's proper height, and reducing pain because the nerves are no longer pinched.
Only when all other conservative treatments have failed will your doctor suggest fusion surgery. Over the past 40 years, lumbar spinal fusion has become the standard of care in the management of several pathologic conditions. The following conditions may require a spinal fusion:
- degenerative disc disease
- spinal instability
- spine curvature
- spondylolysis and spondylolisthesis
- facet joint problems
- spinal trauma
A number of advances in technology have improved the success of spinal fusion, giving surgeons better materials and procedures to work with.
My Doctor has recommended lumbar spinal fusion. What fusion treatment options are there?
Due to advances in medical technology, patients suffering from pain due to degenerative conditions now have more options than ever before. Each option has its own set of risks and benefits. Generally speaking, each procedure is defined by the "approach", or the way in which the surgeon accesses the spine. There are several fusion treatment approaches, including traditional approaches such as anterior, posterior and posterolateral, a combination of anterior and posterior, and the latest approach is lateral.
Description: Anterior Lumbar Interbody Fusion (ALIF) is a common fusion procedure which is done from the front (anterior) of the body, usually through a three to five inch incision (open surgery) in the lower left abdominal area. 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. An intervertebral fusion cage is placed into the area between the vertebrae where the disc has been removed. The greatest advantage of anterior lumbar surgery is that back muscles and nerves are undisturbed, so recovery time is shorter compared to recovery for surgery that requires a posterior approach. Secondly, the fusion area is in the front of the spine where it is compressed, which tends to produce better fusion results. If the fusion becomes solid, the patient has a better chance of a permanent recovery without requiring reoperation. Although this approach spares the back from trauma, it requires delicate manipulation of the major blood vessels in front of the spine. In men, there is also the possibility of damage to the nerves leading to a valve that controls ejaculatory functions.
Recovery: Many patients spend 3-4 nights in hospital. This approach (from the front) does not leave the patient as sore as the approach from the back but it can take some time for the bowels to normalize. Patients are generally not required to wear a back brace after surgery, but some patients may be issued a soft or rigid lumbar brace that can provide additional lumbar support in the postoperative period (which is basically a support for the lower back and is worn like a corset). At 8-12 weeks after surgery, patients usually will be given a prescription to begin physical therapy for gentle back exercises.
Description: Posterior Lumbar Interbody Fusion (PLIF) is a common fusion technique similar to ALIF, however the vertebrae are reached through an incision in the patient's back (posterior). There are two different types of posterior interbody fusion procedures. The traditional posterior lumbar interbody fusion (PLIF) procedure involves placing two small bone graft cages; one graft on each side of the interbody space (right and left). A newer technique, called a TLIF (transforaminal lumbar interbody fusion), involves placing only one bone graft cage in the middle of the interbody space, without retraction of the spinal nerves. The TLIF technique involves approaching the spine more from the side of the spinal canal through a midline incision in the patient's back. Like PLIF, significant disruption to the muscles, bones, and ligaments of the back can occur—although limited to one side of the back.
An incision is made in the middle of the lower back over the area of the spine that is going to be fused. The muscles are moved 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 is removed to take 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 thickening of the ligaments. The surgeon can remove or trim these structures to relieve the pressure on the nerves. Once the surgeon is satisfied that all pressure has been removed from the nerves, a fusion is performed. When operating from the backside of the spine, the most common method of performing a spinal fusion is to place strips of bone graft over the back surface of the vertebrae. This approach can be just a fusion of the vertebral bones or it can include removal of the problem disc. If the disc is removed, it is replaced with a bone graft cage. The surgeon moves the spinal nerves to one side and inserts the intervertebral fusion cage between the vertebral bodies. Small metal rods and screws are placed in the upper and lower vertebral bodies, which will provide immediate stability while the bone mends and to increase the fusion rate (percentage of patients where the bone successfully mends together). With the posterior (back) approach, a much larger incision is required and muscles must be cut, usually resulting in a much longer, more painful recovery.
Recovery: With the posterior approach, most patients are usually able to go home 4-7 days after surgery. Patients are instructed to avoid bending at the waist, lifting (more than five pounds), and twisting in the early postoperative period (first 2-4 weeks) to avoid a strain injury. Patients can gradually begin to bend, twist, and lift after 4-6 weeks as the pain subsides and the back muscles get stronger. At 8-12 weeks after surgery, patients usually will be given a prescription to begin physical therapy for gentle back exercises.
Working between the vertebrae from the back of the patient has limitations. The surgeon is limited by the fact that the spinal nerves are constantly in the way. These nerves can only be moved a slight amount to either side. This limits the ability to see the area. There is also limited 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 are usually performed at the same time, but they may be done several days apart.
Description: The extreme lateral interbody fusion (XLIF®) procedure is considered to be a Minimally Invasive Spinal (MIS) surgery (use of laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or similar device, and are carried out through small incisions in the skin). When performing the XLIF® procedure, your surgeon will approach your spine from the side of your body. You will be positioned on your side on the surgical table and two small incisions will be made. One of the incisions will be made on your side—this is the incision from which most of the surgery will be performed. Another incision will be made slightly behind the first, toward your back. This approach does not require disruption of the sensitive back muscles, bones, ligaments, or nerves and allows for a majority of the disc to be safely removed and implant insertion as compared with traditional posterior procedures. It also does not require the delicate abdominal exposure or present the same risk of vascular injury as traditional anterior approaches. As a result, operating time is often reduced, patient blood loss is minimized, and recovery times are significantly reduced. The surgery is performed through a muscle that lies next to the lumbar spine known as the psoas muscle. After the disc is removed, an artificial graft is placed in between the vertebrae, to allow the bones to fuse together. For a single level XLIF procedure, the surgery can be usually be performed in about an hour. Most patients stay in the hospital for 24 hours following the procedure, and do not require a brace. Not everyone is a candidate for this surgery, once conservative (non-operative) treatments have failed, you should consult a surgeon to see if you are an appropriate candidate.
Recovery: XLIF is a minimally invasive procedure that offers major advantages for both the patient and the surgeon. It requires a smaller incision and is less traumatic to the body’s normal tissues, resulting in a faster, less painful recovery. Patients are typically walking the same day after surgery and require only an overnight stay in the hospital, compared to several days of immobility and hospitalization typical of traditional open approaches. Rapid return to normal activity, typically weeks, compared to months.
Instrumentation to aid in fusion.
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..
Over the past two decades, some very inventive devices have been designed that 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 be used to perform a spinal fusion between two or more vertebrae. These implants are designed to spread the two vertebrae apart while the fusion heals.
Because fusion immobilizes a section of spine, a possible complication of the surgery is additional stress on adjoining segments of the spine which can lead to their progressive deterioration. Failure of the grafted bone to fuse as intended is another possible complication.
The back is pivotal to almost every move we make. Although back pain is all too common, in most cases it's not too serious. Severe back pain that takes you out of your normal routines should not be ignored, however.
Severe back pain warrants an evaluation by your physician with a treatment plan to help you through the immediate distress and a long-term plan for managing disc disease, including the option of surgery if more conservative treatment fails. Fortunately, you have many options if fusion surgery is recommended.
Back to top