Lumbar fusion, or spinal fusion, is a procedure that fuses together damaged vertebrae to create a single, solid bone. This procedure may be used to relieve pain from a number of back disorders, including:

• Spondylolisthesis
• Spinal stenosis
• Degenerative disk disorder
• Scoliosis
• Spinal fracture
• Spinal infection
• Spinal tumor

Spinal fusion eliminates movement between damaged vertebrae. The goal is to eliminate pain by eliminating movement between the painful disks of the vertebrae. Lumbar fusion may also prevent the stretching of nerves, ligaments and muscles in the affected regions. While there may be some loss of motion after spinal fusion surgery, most surgeries affect only a small area, so loss of range of motion is limited as much as possible.

The procedure

This surgery may be performed through one of three approaches:

• Anterior (from the front)
• Posterior (from the rear)
• Lateral (from the side)

Lumbar fusions may be performed using a minimally invasive technique. The approach used depends on the condition of the patient and the nature and location of their damaged vertebrae.

Bone grafts

Lumbar fusion surgery requires the use of bone grafts. This promotes bone fusion and stimulates bone healing. The three types of bone grafts are:

• Autograft: Bone comes from the patient's hip (iliac crest), which has a higher number of bone-growing cells and proteins.
• Allograft: Bone comes from a donor, generally a cadaver.
• Artificial: Manmade plastic, ceramic or other compounds is used to create a graft.

Autograft is considered the gold standard for rapid healing and spinal fusion, but the harvesting of bone cells can be painful. Spinal fusion may produce some loss of motion, particularly in a multilevel discectomy. Artificial disks have been developed that may preserve the range of motion in the neck.

Artificial bone graft materials

Several artificial bone graft materials have been developed, including:

• Demineralized bone matrices (DBMs): Usually used in combination with other bone grafts, DBM uses calcium from cadaver bone to create a material with a putty-like consistency.
• Bone morphogenetic proteins (BMPs): These highly powerful synthetic proteins encourage solid bone fusion. BMPs may eventually overtake autografts in lumbar fusion surgeries.
• Ceramics: These calcium and phosphate materials may be crafted to be similar in shape and consistency to autograft bone.

Possible complications

Any surgical procedure may have complications. With lumbar fusion, there are several potential complications that may require attention, including:

• Nerve damage: While very rare, there can be damage to nerves or blood vessels in the course of this surgery.
• Pain at site of bone graft: Some patients may feel persistent pain at the site of the bone graft.
• Pseudarthrosis: More likely in patients who smoke, this condition is where the bone cells do not properly fuse, and may require an additional surgery to obtain proper fusion.
• Infection: Patients are given antibiotics before, during and after surgery to reduce the risk of infection, but infection can be a risk.
• Blood clots: While uncommon, blood clots can occur in the patient’s legs, and can pose a danger if they break off and travel through the bloodstream.

Complications from blood clots are most likely to happen the first few weeks after surgery, and may include symptoms such as:

• Pain in the calf muscles
• Tenderness or redness above or below the knee
• Swelling in the calf, ankle or foot

If a blood clot breaks loose and travels through the bloodstream, it may settle in your lungs. You may feel sudden chest pain and shortness of breath or cough. If you feel this, contact your physician immediately, go immediately to the emergency room or call 911.

Signs of infection include shaking, chills, fever of over 100° F, and drainage from the wound. If you experience these symptoms, you should contact your physician immediately or go to the nearest emergency room.