Lumbar fusion, or spinal fusion, describes a procedure to fuse together damaged vertebrae (bones of the spine) to create a single, solid bone. It may relieve pain from a number of back disorders, including:
- Spinal stenosis
- Degenerative disc disorder
- Spinal fracture
- Spinal infection
- Spinal tumor
Spinal fusion eliminates movement between afflicted vertebrae, with the intention being that lack of movement between painful discs should eliminate pain. 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.
This surgery may be performed through one of three approaches:
- Anterior (frontal)
- Posterior (rear)
- Lateral (side)
The anterior approach requires an incision in the lower abdomen, while the posterior approach has the patient on their stomach, with the surgeon operating directly on their back. The lateral approach has the surgeon making incisions in the patient’s side.
Lumbar fusions may also be performed through a minimally invasive technique. Which approach is used depends on the condition of the patient, and the nature and location of their disease.
Whatever the approach, lumbar fusion surgery requires the use of bone grafts. This promotes bone fusion and stimulates bone healing. The three types of bone grafts include:
- Autograft: bone comes from you, taken from the hip (iliac crest), which has a higher number of bone-growing cells and proteins
- Allograft: bone comes from a donor (cadaver)
- Artificial: manmade plastic, ceramic or other compounds
Autograft is 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 multi-level discectomy. Artificial discs have been developed which may preserve the range of motion in the neck.
Artificial Bone Graft Materials
There are several artificial bone graft materials that have been developed, including:
- Demineralized bone matrices (DBMs): usually combined with other bone grafts, this procedure removes calcium from cadaver bone to create a putty-like consistency in the bone
- Bone morphogenetic proteins (BMPs): these highly powerful synthetic proteins encourage solid bone fusion. BMPs may eventually supplant autografts in lumbar fusion surgeries
- Ceramics: these calcium and phosphate materials may be crafted to be similar in shape and consistency to autograft bone
Once the lumbar fusion is performed, your surgeon may recommend the wearing of a back brace to limit motion and give the fused vertebrae time to heal. Another technique used includes use of plates, screws and rods (hardware) to increase the rate of bone healing by holding the bones still and allowing bone growth to envelop them, creating a stronger fusion. Often the internal fixation of this hardware allows patients to move earlier after surgery.
Lumbar fusion takes time, requiring months for the bone cells to heal and properly fuse, although pain relief tends to occur far sooner. Proper alignment will be necessary to facilitate healing, and your doctor and physical therapist will assist in this. As healing continues, activity levels can increase.
Are There Complications?
Any surgical procedure may have complications. In the face of lumbar fusion, there are several particular complications that may result, requiring 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 they received
- Pseudoarthrosis: 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, you should contact your doctor immediately, or be taken immediately to the hospital emergency room or call 911.
Signs of infection may be shaking, chills, fever of over 100° F, drainage from the wound. If you experience these symptoms, you should contact your doctor immediately or go to the nearest available emergency room.