Lumbar Spinal Fusion
Spinal fusion is a surgical technique used to combine two or more vertebrae. Supplementary bone tissue (either autograft or allograft) is used in conjunction with the body’s natural osteoblastic processes. This procedure is used primarily to eliminate the pain caused by abnormal motion of the vertebrae by immobilizing the vertebrae themselves.
Spinal fusion is done most commonly in the lumbar region of the spine, but it is also used to treat cervical and thoracic problems. The indications for lumbar spinal fusion are controversial. People rarely have problems with the thoracic spine because there is little normal motion in the thoracic spine. Patients requiring spinal fusion have either neurological deficits or severe pain, which has not responded to conservative treatment.
Posterolateral fusion places the bone graft between the transverse processes in the back of the spine. These vertebrae are then fixed in place with screws and/or wire through the pedicles of each vertebra attaching to a metal rod on each side of the vertebrae. Interbody fusion places the bone graft between the vertebra in the area usually occupied by the intervertebral disc.
In preparation for the spinal fusion, the disc is removed entirely. A device may be placed between the vertebra to maintain spine alignment and disc height. The intervertebral device may be made from either plastic or titanium. The fusion then occurs between the endplates of the vertebrae. Using both types of fusion is known as 360-degree fusion. Fusion rates are higher with interbody fusion.
Three Types of Interbody Fusion Are:
Anterior lumbar interbody fusion (ALIF)- the disc is accessed from an anterior abdominal incision
Posterior lumbar interbody fusion (PLIF) – the disc is accessed from a posterior incision
Transforaminal lumbar interbody fusion (TLIF) – the disc is accessed from a posterior incision on one side of the spine
In most cases, the fusion is augmented by a process called fixation, meaning the placement of metallic screws (pedicle screws often made from titanium), rods or plates, or cages to stabilize the vertebra to facilitate bone fusion. The fusion process typically takes 6–12 months after surgery. During this time external bracing (orthotics) may be required. External factors such as smoking, osteoporosis, certain medications, and heavy activity can prolong or even prevent the fusion process. If fusion does not occur, patients may require reoperation.
Conditions Treated by Lumbar Spinal Fusion
Symptoms Treated by Lumbar Spinal Fusion
Back pain when sitting, bending or twisting
Bowing of the back
Chronic back pain
Chronic neck pain
Claudication in the legs
Curving of the spine
Lower back pain
Pain in my thigh
Pain from my lower back to my knee
Tingling in my legs
Uneven musculature on one side of the spine