Spinal Fusion

About Spinal Fusion

Spinal fusion permanently joins two or more vertebrae so that they heal into a single solid bone, eliminating painful or unstable motion. It is used for spinal instability, spondylolisthesis, scoliosis and other deformities, fractures, tumors, infections and some cases of degenerative disc disease, and is often combined with decompression of nerves by laminectomy, foraminotomy or discectomy. The fusion bed is prepared and bone graft is placed, using bone from the patient, often from the iliac crest, donor bone, or synthetic substitutes and growth factors such as bone morphogenetic protein. Pedicle screws and rods hold the vertebrae still while the bone heals. Interbody fusion places a cage containing graft between vertebral bodies and can be performed from the back, as in posterior and transforaminal lumbar interbody fusion, from the front, or from the side through the psoas muscle. Anterior cervical discectomy and fusion is the most common fusion operation in the neck. Smoking is well known to impair bone healing and increases the risk of nonunion, called pseudarthrosis. Healing of the fusion is assessed with X ray or CT over the following months. Over time, extra stress on the levels above and below a fusion can contribute to degeneration there, known as adjacent segment disease. Minimally invasive techniques use tubular retractors and percutaneous screws to reduce muscle damage. Artificial disc replacement is an alternative to fusion for selected patients, particularly in the neck, and preserves motion. Spinal fusion was first described in 1911 by the American surgeons Russell Hibbs and Fred Albee.