By: Laurie Edwards for Back1
The FDA has recently approved an artificial spinal disc for patients suffering lower back pain from degenerative disc disease (DDD). In replacing a damaged disc with an artificial one, the device offers a new alternative to spinal fusion surgery.
The artificial disc has been used in Europe for several years. About one in four Americans suffer from back pain each year, many of whom experience some degree of DDD. The disease is usually a result of the combination of age and osteoarthritis, which cause overused spinal vertebrae to become irritated and inflamed over time.
FDA approval of the Charité disc, manufactured by DePuy Spine, occurred after review of clinical studies performed by the company aimed at evaluating its safety in relation to spinal fusion surgery.
The results showed two years after the procedure, patients who opted for an artificial disc did no worse than those who underwent spinal fusion.
Over 200,000 spinal fusion surgeries are done each year in the United States. The procedure consists of the removal of the damaged disc while the remaining vertebrae are fused together by bone grafts, screws and sometimes cages.
While effective, spinal fusion is not always reliable. It can result in a loss of motion in the portion of the spine, as well as additional stress that is placed on adjacent discs. Most patients have to wear a brace for several months after the surgery, and the full recovery can take up to six months.
The artificial disc preserves much of the natural motion of the spine. Patients do not expect to wear braces after the procedure, and the recovery time is usually much less than with spinal fusion.
The plastic disc is placed between two metal endplates and is meant to fully replace damaged discs. After removing the diseased disc, surgeons implant the new one in the spine through an incision made just below the navel. The device helps restore the natural distance between the vertebrae, which can then allow for movement at the spot where the new disc is located.
The new disc may not always allow for movement in some patients, or it can allow for too much, which puts stress on the device. It is not recommended for all people who suffer from DDD, especially the elderly. Those with strong facet joints are the best candidates since these joints are what help maintain movement in the spine.
“If you’re going to preserve motion above and below [the disc] and you’ve got facets that are already having trouble, the two are not going to work together as a team,” said Robert Heary, MD, a New Jersey spokesman for the American Association of Neurological Surgeons.
The practice of replacing other joints in the body, such as hips or knees, with artificial ones has proven hugely successful and is now a routine procedure. Experts hope the same strides will be made with the artificial disc.“This is a quantum step forward in the treatment of lower back pain,” said Charlotte, N.C. neurosurgeon Dom Coric. “It’s just amazing the patient interest behind it.” It is not yet known how long the discs will last and how any ensuing surgeries should be handled. “At least early on it looks good, but that’s about all we know,” said Heary.