There are a couple of alternatives to spine fusion surgery that may be considered for patients with low back pain from lumbar degenerative disc disease. Currently, the main fusion alternatives include:
- IDET. or Intradiscal electrothermal coagulation (or annuloplasty). This procedure involves inserting a needle into the lumbar disc space, passing a catheter through the needle, and heating up the annulus (the outer core of the disc space). The exact mechanism by which the procedure relieves pain has not been clearly established, but it is theorized that the heat contracts and thickens collagen fibers in the disc wall, which in turn seals up painful tears and cracks and reduces pain. The procedure also cauterizes nerve endings which is thought to make them less sensitive. Not all patients benefit from IDET, and the treatment is more likely to help people with less severe degenerative disc disease than people with significant disc degeneration. IDET is minimally invasive and usually done on an outpatient basis (no overnight hospital stay) under mild sedation and a local anesthetic. Although the procedure is minimally invasive it has largely fallen out of favor in the spine world as it has marginal clinical efficacy. Most insurance companies no longer cover the procedure.
Artificial discs. Disc replacement surgery involves replacing the painful disc in the spine with an artificial disc. The goal of artificial disc replacement surgery is to preserve the normal motion of the spine (unlike fusion, which eliminates motion at the painful spinal segment). Artificial disc surgery has two primary theoretical advantages over spinal fusion; 1) it is thought that preserving spinal motion reduces the risk that other segments of the lumbar spine will wear down prematurely; 2) it is believed that artificial disc surgery may achieve better pain reduction than fusion. However, these potential benefits come at the expense of greater risk with the surgery. Any motion preservation device can fail by extrusion or wearing out with time. Revision surgeries are expensive and extremely dangerous. The risk/benefit ratio of artificial disc vs fusion is still largely unknown, and currently many insurance companies are not covering the procedure.
- Posterior dynamic stabilization. This treatment is different from fusion in that posterior dynamic stabilization seeks to preserve motion in the spine while also taking pressure off the diseased vertebral disc. The theory is that removing pressure from the painful disc will create a favorable healing environment and reduce pain. The devices used in the surgery are designed to unload pressure from the vertebral disc in the same way a dynamic (moveable) brace unloads pressure from an injured knee or ankle to allow it to heal. Various forms of posterior dynamic stabilization devices are still in the investigative or testing phase or early in use, and their efficacy and potential risks and complications have not yet stood the test of time.
- Disc regeneration. Researchers in cellular and molecular biology are exploring ways to use gene therapy to stimulate regeneration of the vertebral disc and/or to slow or prevent degeneration of the disc. The hope is that this therapy could prevent the need for surgery. For example, in animal studies, the BMP-12 gene (bone morphogenetic protein) has dramatically increased the generation of cells in both the nucleus and the annulus of the vertebral disc. BMP-12 is a molecule that, among other duties, promotes formation of embryonic joints. Research is also being performed on gene therapy that could inhibit the degeneration process. Gene therapy for treatment of the intervertebral disc is still in the early stages of research.