Back Surgery: Lumbar Spinal Fusion Surgery
There are several variations of the back surgery known as lumbar spinal fusion surgery. All variations of this back operation are designed to restore stability to the spinal column that has been lost due to degenerative changes of the facet joints, changes in the shape of the vertebral bones due to a congenital condition, or to disease. Usually, the operation, performed under general anesthesia, is designed to reduce the motion as a painful vertebral segment by permanently fusing the two bones together. The process of fusion is done with a piece of bone that is usually grafted off the hip or pelvis, where it is placed between the two bones to be locked together, and permanently attached mechanical devices such as rods and screws to create one immobile segment. the graft taken off the him and connected between the two vertebral segments causes bone graft to grow between the two vertebrae, creating one permanent piece. Unlike other back surgeries, spinal fusion patients come from many different age groups and have a much greater variety of medical conditions contributing to their back pain and instability of the spine. For example, more pediatric and young patient requires lumbar spinal fusion surgery, due to congenital conditions such as scoliosis and isthmic, degenerative or postlaminectomy spondylolisthesis. Other conditions that may destabilize the spinal column and be successfully treated with this procedure include degenerative disc disease spine tumors, and infection.
How Spinal Fusion Works: At each level of the spine, the connection between the vertebral bone above and below it is to the disc and above and below intervertebral disc and facet joint above and below it. The intervertebral discs and the ligaments and tendons allow for some movement and the facet joints provide enough stability to keep the entire spine moving as a single unit. Working together, all these parts allow us to twist and bend, within a normal range of motion. Due to a wearing out of the facet joints, or degenerative changes to the bones, discs, or other structure(s), the spine at one or more segments along it may begin to move in a unnatural or unstable way that threatens the spine or causes us to feel a degree of pain. For some patients, it may be determined necessary to fuse the spine at two or more segments to stop its motion and stabilize it.
Patients may need a one-level spinal fusion (meaning the fusion of just one set of vertebral bones to another) or may need a fusion between more than two segments. Though an operation could involve the fusion of several segments, a patient who only requires a one-level spinal fusion is significantly to have a better long term prognosis as a result. Typically, the bone graft used to fuse two or more segments together is taken from the patient (hip or pelvis), though bone to be grafted may be taken from a cadaver bone or manufactured (synthetic bone graft substitute).
Patients who have only two segments fused and who recover well from the procedure will not usually feel the difference, in terms of stiffness and range of motion issues.