Spinal Fusion Using Gene Therapy

What do pigs, gene therapy, and the human spine have in common? Until 10 years ago, exactly nothing. But now the field of gene therapy is bringing many things together in the laboratory. Gene therapy is the science of replacing genes or other defective cells. Gene therapy may be able to help heal injuries or replace worn-out tissue.

In the spine, disc degeneration from aging or injury can lead to chronic back pain. Today's treatment for this problem is to remove the disc and fuse the spine. Bone graft is used to join two or more bones together. Metal plates and screws may be used to hold the bones together as they heal, or fuse.

This study looks at the possibility of fusing the spine using gene therapy. The gene for bone growth is injected into the disc space. The idea is for it to trigger enough bone growth to connect the bone on either side of the space.

In the past, rats were used to study gene therapy to fuse bones together. This is the first study to use mammals, an important step before studying humans. Two groups of pigs were used. One gorup received gene therapy, and a second group (the control group) didn't receive gene therapy.

Within seven days, bone formed in the disc spaces in the group that got gene therapy. Solid bone formed across all the disc spaces in the treated group. No bone growth was seen in the control group.

Only a small number of pigs was used. The purpose of the study was simply to see if the gene therapy method of bone fusion would work. The next step is to repeat this study with a larger number of mammals. In time, researchers may be able to get similar results in humans. An easily injectable method of bone fusion could replace the costs and complications of spinal fusion surgery.