Definition and Overview
Lumbar spinal fusion is a spine surgery used to join or fuse two or more vertebrae in the lumbar spine, the lower portion of the spine found at the curve of the lower back, just below the rib cage. This area is a common source of back pain, which may be due to certain conditions that affect the nerves. Some of these conditions may cause the tissue surrounding the bones to become extremely tender and painful. The purpose of lumbar spinal fusion is to eliminate pain by fusing two vertebrae together to allow solid growth.
A lumbar spinal fusion surgery can be performed alone or in conjunction with another surgery that removes bone and tissue that are narrowing the spinal canal and squeezing the spinal cord and/or the spinal nerves. Removing the intervertebral disc or bone spurs eases the pressure on the nerves, and thus also relieves the patient’s pain. Fusing the vertebrae together also stops the formation of bone spurs, and therefore also prevents recurrent pain.
This procedure is similar to a cervical spine surgery, except that it is performed on the lower back area of the spine instead of the upper neck area. However, the process and techniques used in a lumbar fusion and cervical fusion bear some similarities.
Who Should Undergo and Expected Results
Spinal fusion is recommended for patients who suffer from the following conditions:
Degenerative disc disease
Unstable spinal column
Conditions that cause spinal instability
It may also be done as a follow-up procedure for patients who have previously undergone surgery for the following conditions:
After the surgery, patients are advised to stay in the hospital for a few days for close monitoring. The doctor will determine when it is safe for the patient to return home.
While recovering at home, patients do not need to be on bed rest, as long as they wear a back brace to protect their spine and ensure spinal stability during the healing process. During the recovery process, patients can expect their symptoms to disappear gradually as the area also begins to get stronger.
Since it is a major procedure, rehabilitation can also take a long time. A common rehabilitation plan for patients who have undergone lumbar spine fusion includes walking, riding a stationary bike, swimming, and similar activities. These activities can help strengthen the muscle that supports the spinal column as well as enhance healing.
How is the Procedure Performed?
A spinal fusion surgery is a major procedure that usually lasts for three to four hours. The bones may be fused together using different techniques. The process begins by taking the bone either from the pelvic bone (an autograft) or a bone bank (an allograft). The bone is then used to bridge the gap between two adjacent vertebrae. Metal implants, such as rods, screws, and plates, are also used to hold the vertebrae together.
The surgeon can use different types of bone grafts, which also affects the specific method used during the procedure. The following are some examples of bone grafts used in a lumbar spine fusion procedure:
Strips of bone graft material that are placed over the back part of the spine
Bone graft materials that are placed between the vertebrae
Special cages packed with bone graft material that are placed between the vertebrae
Regardless of the specific technique used, a lumbar fusion procedure typically follows the same process. First, the patient is placed under general anesthesia, during which he or she will be completely asleep and unable to feel anything. Once the patient is asleep, the surgeon will make a surgical incision to gain access to the spine. If another procedure is necessary, it is usually done first. These may include a discectomy, laminectomy, or a foraminotomy. After this, the spinal fusion can be performed.
The specific location of the surgery may differ, which also affects the patient’s position during the procedure. The surgery may be performed:
On the patient’s back or neck over the spine, which means the patient has to lie face down during the neck surgery
On the lower back, which means the patient has to be lying on his side. For the surgeon to gain proper access to the lumbar spine during the back surgery, he will have to use retractors to separate the soft tissues and blood vessels while he is performing the procedure.
On the front of the neck, usually toward the side, which means the patient will be on his back throughout the surgery.
Nowadays, however, lumbar spine fusion surgery can also be performed in a minimally invasive way. This means that a big surgical incision is no longer necessary. This new technique helps reduce the risks of the surgery and speeds up the patient’s recovery process.
Possible Risks and Complications
The risks of lumbar spine fusion depend on the patient’s age, overall health condition, and the type and purpose of the procedure. These include:
Pain at the bone graft site or the area of the fused spine
Blood clots, which could result in a pulmonary embolism
Residual nerve pain – This can be eliminated through exercise and back support. In the case of obese or overweight individuals, weight reduction may also help.
Infection – Signs of infection may include redness, swelling, and tenderness either around the bone graft site or the surgical wound over the fused spine.
Poor or slow healing – Healing after a lumbar spine fusion may take several months, but the symptoms are expected to lessen in intensity. If symptoms seem to be increasing or if they seem to be taking a longer time than usual to disappear, patients should inform their healthcare provider.
Breakage of metal implants
To prevent risks and complications, patients should pay attention to their diet and lifestyle habits. The right diet and lifestyle changes may help prevent risks from occurring. Also, post-surgical exercises and rehabilitative activities should be done only with the approval and under the close monitoring of a trained professional.
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“The truth about spinal fusion.” Journal of the Spinal Research Foundation. http://spinerf.org/wp-content/uploads/2015/12/merged-3.pdf
El Tecle NE, Dahdaleh NS. “Fusion surgery for lumbar spinal stenosis.” N Engl J Med 2016; 375:597-601. http://www.nejm.org/doi/full/10.1056/NEJMc1606502#t=article