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. 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’s no longer space between them.

Spinal fusion is also known as:

  • arthrodesis
  • anterior spinal fusion
  • posterior spinal fusion
  • vertebral interbody fusion

Spinal fusion is performed to treat or relieve symptoms of many spinal problems. The procedure removes mobility between the two treated vertebrae. This may decrease flexibility, but it’s useful for treating spinal disorders that make movement painful. These disorders include:

A spinal fusion procedure may also include a discectomy. When performed alone, a discectomy involves removing a disc due to damage or disease. When the disc is removed, bone grafts are placed into the empty disc space to maintain the right height between bones. Your doctor uses the two vertebrae on either side of the removed disc to form a bridge (or fusion) across the bone grafts to promote long-term stability.

When spinal fusion is performed in the cervical spine along with a discectomy, it’s called cervical fusion. Instead of removing a vertebra, the surgeon removes discs or bone spurs from the cervical spine, which is in the neck. There are seven vertebrae separated by intervertebral discs in the cervical spine.

Typically, the preparation for spinal fusion is like other surgical procedures. It requires preoperative laboratory testing.

Before spinal fusion, you should tell your physician about any of the following:

  • cigarette smoking, which may reduce your ability to heal from spinal fusion
  • alcohol use
  • any illnesses you have, including colds, the flu, or herpes
  • any prescription or over-the-counter medications you’re taking, including herbs and supplements

You’ll want to discuss how the medications you’re taking should be used before and after the procedure. Your doctor may provide special instructions if you’re taking medications that could affect blood clotting. These include anticoagulants (blood thinners), such as warfarin, and nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin and ibuprofen.

You’ll be given general anesthesia, so you’ll need to fast for at least eight hours before your procedure. On the day of surgery, use only a sip of water to take any medications your physician has recommended.

Spinal fusion is performed in the surgical department of a hospital. It’s done using general anesthesia, so you won’t be conscious or feel any pain during the procedure.

During the procedure, you’ll be lying down and have a blood pressure cuff on your arm and heart monitor leads on your chest. This allows your surgeon and anesthesia provider to monitor your heartbeat and blood pressure during surgery. The whole procedure may take several hours.

Your surgeon will prepare the bone graft that will be used to fuse the two vertebrae. If your own bone is being used, your surgeon 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’re having a cervical fusion, your surgeon will often 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 affected vertebrae to join them. Sometimes, the graft material is inserted between the vertebrae in special cages. Some techniques place the graft over the back part of the spine.

Once the bone graft is in place, your surgeon may use plates, screws, and rods to keep the spine from moving. This 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.

After your spinal fusion, you’ll need to stay in the hospital for a period of recovery and observation. This generally lasts three to four days. Initially, your doctor will want to observe you for reactions to the anesthesia and surgery. Your release date will depend on your overall physical condition, your physician’s practices, and your reaction to the procedure.

While in the hospital, you’ll receive pain medication. You’ll also get instructions about new ways you may need to move, since your flexibility may be limited. 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 you leave the hospital you may need to wear a brace to keep your spine in proper alignment. You might not be able to resume your normal activities until your body has fused the bone into place. Fusing may take up to six weeks or longer. 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’ll heal and be able to return to your usual activities.

Spinal fusion, like any surgery, carries the risk of certain complications, such as:

  • infection
  • 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.

The hardware will need to be removed if it’s producing pain or discomfort.

Contact your doctor or seek emergency help if you experience any of these symptoms of a blood clot:

  • a calf, ankle, or foot that suddenly swells
  • redness or tenderness above or below the knee
  • calf pain
  • groin pain
  • shortness of breath

Contact your physician or seek emergency help if you experience any of the following symptoms of infection:

  • swelling or redness at the edges of the wound
  • drainage of blood, pus, or other liquid from the wound
  • fever or chills or elevated temperature over 100 degrees
  • shaking

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 your movements. And while the procedure might not relieve all of your chronic back pain, you should have a general reduction in pain.

However, since the procedure 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. They may become painful if they deteriorate and you may experience additional problems.

Being overweight, inactive, or in poor physical condition can also 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.