Lumbar fusion is a type of spinal fusion surgery in which two or more bones in the lower back are fused together. It is usually performed on patients who have chronic low back pain resulting from an injury or from degenerative changes in the spine such as arthritis. Lumbar fusion is sometimes used to correct scoliosis as well. It is usually done after more conservative approaches, such as physical therapy and bracing, have failed to alleviate low back pain.
Low back pain is one of the most common medical complaints. It can be caused by injuries sustained in auto accidents or sports, misalignment of spinal bones because of scoliosis, or normal changes in the spine resulting from aging. The lumbar spine consists of the five largest bones in the spinal column, located at the lower, inward-curving part of the back and the top of the hips. When the vertebrae in this area become compressed or unstable, they can press on the surrounding spinal nerves, causing low back pain as well as numbness and tingling in the legs and feet. Degenerative disk disease and severe arthritis of the spine can also cause the vertebrae to rub against each other as they move, creating pain and possible disc injury. Lumbar fusion surgery may alleviate the pain by preventing this bone-on-bone movement.
In a lumbar fusion procedure, a surgeon fuses, or connects, two or more of the lumbar bones together, preventing any motion between them. One common method used is bone grafting, which can be done with the patient's own bone harvested from the hip, donor bone from cadavers, or synthetic bone-like material. Metal screws and rods are sometimes affixed to the vertebrae to hold the position of the graft. As the graft heals, the patient's body will generate new bone growth between the two fused vertebrae, permanently connecting the two bones together and alleviating the pain associated with the motion of the separate bones. Sometimes the surgeon will remove the disc between the vertebrae if it is ruptured, inflamed, or otherwise damaged.
The risks associated with lumbar fusion are similar to other surgeries and include reaction to anesthesia, infection, and pain at the surgical site. There is a slight possibility of graft rejection with this procedure, and some loss of spinal mobility may occur if more than two vertebrae are fused together. Surgery is usually followed by a treatment plan that includes physical therapy and follow up tests to ensure that the spinal alignment is maintained.