by Maria Adams, MS, MPH, RD
Anatomy and Physiology
The spine consists of a series of interconnected bones, called vertebrae, extending from the base of the skull to the tailbone. There are five different regions of the spine: the cervical, thoracic, lumbar, sacrum, and coccyx regions.
Protected within this vertebral column is the spinal cord, which connects the brain to the rest of the body. Spinal nerves, or nerve roots, emanate from the spinal cord at regular intervals. The spinal cord is bathed in cerebrospinal fluid and surrounded by a protective membrane called the dura. In between each bony vertebra lies a shock- absorbing intervertebral disc.
Each spinal nerve passes through a narrow opening between the vertebral bones and behind the intervertebral discs. Spinal nerves in the lumbar, or lower back, region come together to form the larger nerves that pass into the legs.
Each vertebra connects with the one above and below at the facet joints, allowing them to move relative to one another. The facet joints and intervertebral discs work together to permit the bending and twisting motions of the back and neck.
Conservative treatment of acute back or neck pain begins with 1-2 days of rest followed by gradually increasing activity. If the pain becomes a chronic problem, doctors often prescribe exercises to stretch the ligaments and strengthen the muscles around the spine. Depending on the diagnosis, doctors may also recommend physical therapy and/or medications to relieve the pain and inflammation.
When conservative treatments are unsuccessful, doctors may inject medications into the space surrounding the spinal cord at the affected level. Steroid injections, the most commonly prescribed, produce a temporary anti-inflammatory effect and are commonly used to treat spinal osteoarthritis and intervertebral disc herniations.
Surgery is the last treatment option and should be performed only when all other attempts have failed to relieve symptoms. Sometimes doctors will remove part of the bone next to the spinal nerve, called the lamina. This procedure, called a laminectomy, can take some pressure off the nerve or the spinal cord. If a herniated disc is compressing a spinal nerve, all or part of it may be removed in a procedure called a discectomy.
In a spinal fusion, a bone graft from either the patient's hip or another donor is used to force two or more vertebral bodies to grow together into one long bone. It may be done alone or in conjunction with a laminectomy or discectomy. The surgery is most effective when only one vertebral segment is the source of pain.
In the days leading up to your procedure: discuss with your doctor the option of donating your own blood for use during the surgery if necessary. Arrange for a ride to and from the hospital and for help at home as you recover. The night before, eat a light meal and do not eat or drink anything after midnight. Your doctor may ask you to temporarily discontinue certain medications, herbs, or dietary supplements that you regularly take, especially those that can thin the blood, including aspirin and other non-steroidal anti-inflammatory medications. Do not start taking any new medications, herbs, or dietary supplements before consulting your doctor.
Before the procedure, an intravenous line will be started. A catheter may be placed in your bladder to drain your urine. Spinal fusions are done under general anesthesia, which means you will be asleep for the duration of the operation. A breathing tube will be inserted through your mouth and into your windpipe to help you breathe during the procedure.
Your surgeon will choose the type of spinal fusion to perform. Depending on the reason for the surgery, he or she will gain access to your spine through an incision in the front or back, or through a combination of both. Fusions of the lower spine are usually approached from the back, in which case you will lie on your stomach and your surgeon will make an incision directly over the spine. Surgery on the cervical spine in the neck, on the other hand, is generally approached from the front.
In some cases, a spinal fusion may be performed using a newer, less invasive laparoscopic technique. Rather than one or two large incisions, a laparoscopic spinal fusion requires several tiny, "keyhole" incisions, through which the laparascope and special surgical instruments are inserted.
If necessary, your doctor will also perform a laminectomy and/or discectomy before moving the bone graft into place for the spinal fusion.
If your surgeon is using your own bone for the fusion, he or she will make an incision overlying your hip, remove a bone graft, and transfer it to the area to be fused. If your bone graft is coming from another donor, it will be harvested prior to your procedure. Donor grafts are specially treated to minimize any risks of communicable diseases. Grafts from other donors are most often used in smokers or other patients with wound healing problems.
Using a high-speed drill and other instruments, your surgeon will remove the disc between the two vertebral bodies to be fused. Next, your surgeon will insert the bone graft into the space between these two vertebrae. He or she may also place a plate and screws over the graft to hold the vertebrae together until they fuse into one bone.
To complete the procedure, your surgeon will close the deep tissue and skin incisions in your back with stitches. Many surgeons will also place on or more drains beneath the skin that remain in place for a few days.
Risks and Benefits
Possible risks and complications of a spinal fusion include: excessive bleeding requiring a blood transfusion, wound infection, temporary increase in back or neck pain, persistent or worsening back or neck pain following the surgery, damage to the spinal cord or spinal nerve, resulting in numbness and/or weakness, urinary retention or incontinence, complications at the bone graft donor site, including infection or chronic pain, failure or improper placement of hardware, spinal fluid leakage, failure of bones to fuse together, blood clots in the legs that may travel to lungs, injuries to major blood vessels, windpipe, or organs, depending on the location of the surgery, ejaculation problems in men, and/or adverse effects from general anesthesia.
Potential benefits of a spinal fusion include: decreased back or neck pain, less reliance on medications and other treatments for persistent pain, prevention of worsening neurologic deficits in cases of serious spinal cord or nerve root compression, improvement of spinal alignment and curvature.
In a spinal fusion, or any procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it's the most appropriate treatment choice for you.
After the Procedure
After your procedure you will be taken to a recovery area for monitoring. The bladder catheter will likely remain in place for several days. You may be unable to eat for a day or two after surgery, and will receive fluids and nutrition through the IV. Some pain is expected during the first few days following surgery, and you will be provided with pain medication to control it.
The usual hospital stay following a spinal fusion is 3-4 days, but may be longer depending on the extent of your surgery. Because the fused spine must remain in proper alignment, you will be taught to sit, move, walk, and stand in a certain way prior to discharge.
Following discharge, you will be advised to wear a brace or cast for up to three months. Your surgeon will recommend a rehabilitation program to aide in your recovery and may discharge you to an inpatient rehabilitation unit for a period of time before you return home.
Once home you should contact your surgeon immediately if you experience: signs of infection, such as fever and chills, persistent nausea or vomiting, redness, swelling, increasing pain, excessive bleeding, or discharge at the site of your incision, cough, shortness of breath, or chest pain, pain, burning, urgency, or frequency of urination, inability to control your bowel or bladder, numbness, weakness, or increasing pain in your arms or legs, and/or increasing pain in your back or neck.
It will take a while for you to return to your normal lifestyle. You will need to follow up with your surgeon on a regular basis. Once he or she sees evidence of bone healing, usually six weeks following surgery, you may begin to return to your normal routine. Substantial healing takes 3-4 months, and complete recovery takes even longer.
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