Copyright 2010 American Academy of Orthopaedic Surgeons
Posterolateral Lumbar Fusion

Spinal fusion is a surgical procedure used to correct problems with the small bones in the spine (vertebrae). It is essentially a "welding" process. The basic idea is to fuse together the painful vertebrae so that they heal into a single, solid bone.

This article focuses on just the surgical component of posterolateral lumbar fusion. For a complete overview of spinal fusion, including approaches, bone grafting, complications, and rehabilitation, please go to Artifical Disk Replacement in the Lumbar SpineArtifical Disk Replacement in the Lumbar Spine (topic.cfm?topic=A00502).

Posterolateral Fusion

In a posterior approach to lumbar fusion, the surgeon makes an incision down the middle of the lower back. To see the vertebrae, the surgeon will pull back the muscles that surround the spine. In many cases, the surgeon will remove arthritic bone and other structures that may be putting pressure on spinal nerves. This is called a decompression, or laminectomy.

A posterior approach to lumbar surgery. An incision is made over the vertebrae that will be fused.
(Left) Muscles surrounding the spine are pulled back to expose the bone. (Right) After a decompression, bone graft material and screws are placed along the sides of the vertebrae.

After the decompression, the surgeon will place graft material along the sides of the vertebrae to stimulate bone growth. This is called a posterolateral fusion. Titanium screws and rods are often used to provide immediate stability to the spine until a solid fusion has been achieved. These screws typically are not removed even after the bone graft has healed.

Back and side views of posterolateral fusion with screws.
Last reviewed: June 2010
AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS "Find an Orthopaedist" program on this website.
Copyright 2010 American Academy of Orthopaedic Surgeons
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