by Lisa Hanchey

The Charité Artificial Disc consist of a moveable high-density plastic center sandwiched between two medal endplates.

On May 5, Lafayette neurosurgeon Alan Appley became the first Acadiana physician to perform spine surgery using an artificial disc. He proudly reports that the procedure "went very well," then modestly adds, "it's kind of a beginner's luck thing."

Dr. Appley used the Charité artificial disc, which was just approved by the FDA in October, to execute this breakthrough procedure. Similar to the implant used for hip and knee replacement, this device consists of two metal endplates encasing a sliding core. The endplates are fabricated from medical grade cobalt chromium alloy, while the core consists of a movable plastic. Small external "teeth" affix to the vertebrae above and below the disc space to secure the implant.

Traditionally, surgeons perform fusions to relieve symptoms from a degenerated or herniated disc. However, this procedure leaves the surrounding vertebrae immobilized, limiting movement in the spine. By contrast, the artificial disc design maintains spine flexibility and range of motion. "The idea with the artificial disc is to both reestablish the height of the disc space to relieve the pressure on the nerves, and also to get back to the normal motion of that disc space," Appley explains.

Because the procedure is so new, surgical candidates are required to meet stringent criteria. Currently, artificial disc replacement is limited to patients with one level of diagnostically-confirmed disc disease between either L4 and L5 or L5 and S1. These clients must have primarily low back pain, with or without leg pain. Additionally, they need to undergo six months of failed conservative treatment, such as medication, physical therapy or chiropractic care.

Appley confirms that patient selection is the most important factor. He says that younger prospects are ideal, because "the younger the patient is, the more important it is to preserve the motion at those segments we are operating on." But, he emphasizes that older patients in their forties and fifties could also be good candidates.

Fortunately for Appley, his first artificial disc recipient was a "perfect" fit. This patient was a 29-year-old who had sustained a back injury in an offshore lifting accident. He complained primarily of back pain and some leg pain, but not enough to exclude him from the procedure. He had finished the required course of conservative treatment. And, most importantly, he was willing to wait through the lengthy approval process. "We had been seeing him for several months, and he was willing to wait for the disc to come out and be approved and for us to get trained," Appley says. "I think that if this had been a year off until we could have gotten something done or if he hadn't considered it, we probably would have just done a fusion."

Appley attributes "good timing" to how he became the first surgeon in Acadiana to perform the artificial disc replacement. So far, he is the only neurosurgeon in this area to complete the training. Lafayette orthopedic surgeons John Cobb and David Muldowny have also qualified to do the procedure. "The only reason really that mine was first was because this guy happened to have very forward thinking and it was easy to work with the worker's compensation company," Appley says.

Dr. Muldowny has one patient authorized for the procedure, which he expects to perform within the next two to three weeks. He also has several awaiting approval. He says that while he is "very excited" about the potential benefits of disc replacement, he cautions that "this is not a 'cure' for back pain, but rather another option that for some patients maybe be better, long term, than a fusion procedure."

Compared to a fusion, the biggest advantage of the artificial disc replacement is its long-term benefit. Because fusion eliminates a motion segment in the spine, it can potentially put extra stress on the adjacent discs. This accelerates degeneration of segments above and below the fused disc space. The artificial disc, which preserves movement, does not have this adverse effect.

Complications with the artificial disc are comparable to those of fusion patients. Cost-wise, the artificial disc surgery is slightly more expensive than a basic fusion. The list cost of the device alone is $11,500. "I would say, compared to the most basic fusion, it's probably a little bit more expensive, but compared to the way we do a lot of the fusions by adding devices, it's actually very similar," Appley says.

Since the first successful procedure, other potential artificial disc recipients are anxiously awaiting their turns. Right now, the biggest obstacle appears to be educating insurance and workers' compensation carriers about this brand new technology. "For example, one company denied it, saying 'you're approved to do a fusion, but not an artificial disc. And by the way, what is an artificial disc?'," Appley recalls, chuckling.