What Is Spinal Fusion?
Spinal fusion is a surgical procedure in which two or more vertebrae are permanently joined into one solid bone with no space between them. The vertebrae are the small, interlocking bones of the spine.
In spinal fusion, extra bone is used to fill the space that usually exists between the two separate vertebrae. When the bone heals, there is no longer space between them.
Spinal fusion removes mobility between the two treated vertebrae. While some flexibility may be lost, spinal fusion is a useful technique in treating spinal disorders in which movement is the source of pain. The disorders that spinal fusion is used to treat include:
- spinal stenosis
- herniated “bulging” discs
Spinal fusion is also known as:
- anterior spinal fusion
- posterior spinal fusion
- spine surgery
- vertebral interbody fusion
Uses of Spinal Fusion
Spinal fusion is performed to treat or relieve symptoms of many spinal problems, including:
- degenerative disk disease
- fractured vertebrae that may be making your spinal column unstable
- scoliosis (curvature of the spine)
- kyphosis (abnormal rounding of the upper spine)
- spinal weakness or instability due to severe arthritis, tumors, or infections
- spondylolisthesis (a condition in which one vertebra slips onto the vertebra below it, causing severe pain)
When spinal fusion is performed with a diskectomy, it is called cervical fusion. Instead of removing a vertebra, the surgeon removes disks or bone spurs from the cervical spine, which is in the neck. In the cervical spine, seven vertebrae are separated by intervertebral disks.
When a disk must be removed due to damage or disease, it is called a diskectomy. When the disk is removed, bone grafts are placed into the empty disk space to maintain the height relationships between the bones. The two vertebrae on either side of the removed disk are positioned to form a bridge, or fusion, across the bone grafts to promote long-term stability.
Preparing for Spinal Fusion
Typically, the preparations required for spinal fusion are minimal and routine.
Tell your physician about any prescription or over-the-counter medications you are taking, including herbs and supplements. Discuss how they should be used before and after the procedure.
You should also tell your physician about:
- your cigarette smoking, which may reduce your ability to heal from spinal fusion
- your alcohol use
- any illnesses you have, including colds, the flu, or herpes
Your physician may provide special instructions if you are taking medications that could affect blood clotting. Medications that can affect clotting include:
- anticoagulants (blood thinners), such as warfarin
- nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin and ibuprofen
Because you will be given general anesthesia, you will need to fast for at least eight hours before your procedure. On the day of your surgery, use only a sip of water to take any medications your physician has recommended.
How Is Spinal Fusion Performed?
Spinal fusion is performed in the surgical department of a hospital. It is done using general anesthesia, so you will not be conscious or feel any pain during the procedure.
Spinal fusion may take three to four hours to perform. During the procedure, you will be lying face down and have a blood pressure cuff on your arm and heart monitor leads on your chest so that doctors can monitor your heartbeat and blood pressure during surgery.
Your doctor will prepare the bone graft that will be used to fuse the two vertebrae. If your own bone is being used, your doctor will make a cut above the pelvic bone and remove a small section of it. The bone graft may also be a synthetic bone or an allograft, which is a bone from a bone bank.
Depending on where the bone will be fused, your surgeon will make an incision for placement of the bone.
If you are having a cervical fusion with diskectomy, the surgeon will make a small incision in the horizontal fold of the front of your neck to expose the cervical spine. The bone graft will be placed between the vertebrae to join them. Sometimes, the graft material is inserted between the vertebrae in special cages, and some techniques place the graft over the back part of the spine.
Once the bone graft is in place, your surgeon will use plates, screws, and rods to immobilize the spine. This technique is called internal fixation. The added stability provided by the plates, screws, and rods helps the spine to heal faster and with a higher rate of success.
Recovery from Spinal Fusion
After your spinal fusion is completed, you will need a period of recovery and observation before you are released from the hospital. Initially, you will be observed for reactions to the anesthesia and surgery.
You will typically remain in the hospital between three and four days following your spinal fusion. The timing of your release will vary, depending on your overall physical condition, your physician’s practices, and your reaction to the procedure.
While in the hospital you will be given pain medication and instructed about new ways you may need to move to accommodate any limited flexibility. You may need to learn new techniques to walk, sit, and stand safely. You also may not be able to resume a normal diet of solid food for a few days.
After your discharge from the hospital you may need to wear a brace to keep your spine in proper alignment, and you may be limited in what you can do until your body has fused the bone into place. Fusing may take up to six weeks. Your doctor may recommend physical rehabilitation to help you strengthen your back and learn ways to move safely.
Full recovery from spinal fusion will take three to six months. Your age, overall health, and physical condition affect how quickly you will heal and be able to return to normal activities.
Complications of Spinal Fusion
Spinal fusion, like any surgical intervention, carries the risk of certain complications, such as:
- blood clots
- bleeding and blood loss
- respiratory problems
- heart attack or stroke during surgery
- inadequate wound healing
- reactions to medications or anesthesia
Spinal fusion also carries the risk of the following rare complications:
- infection in the treated vertebrae or wound
- damage to a spinal nerve, which can cause weakness, pain, and bowel or bladder problems
- additional stress on the bones adjacent to the fused vertebrae
- persistent pain at the bone-graft site
- blood clots in the legs that can be life-threatening if they travel to the lungs
The most serious complications are blood clots and infection, which are most likely to occur during the first weeks following surgery.
Contact your physician or seek emergency help if you experience any of the warning signs of blood clots:
- a calf, ankle, or foot that suddenly swells
- redness or tenderness above or below the knee
- calf pain
Contact your physician or seek emergency help if you experience any of the following warning signs of infection:
- swelling or redness at the edges of the wound
- drainage of blood, pus, or other liquid from the wound
- fever or chills
Outlook for Spinal Fusion
Spinal fusion is typically an effective treatment for certain spinal conditions. The healing process may take several months. Your symptoms and comfort level will gradually improve as you gain strength and confidence in movement.
Spinal fusion probably won’t relieve all chronic back pain. However, your level of pain will most likely be reduced.
After spinal fusion, you may experience additional problems. Spinal fusion changes how the spine works by immobilizing one portion of it. The areas above and below the fusion are at an increased risk for wear and tear and may become painful if they deteriorate.
Being overweight, inactive, or in poor physical condition, can put you at risk for more spinal problems. Living a healthy lifestyle, with attention to diet and regular exercise, will help you achieve the best results.