For patients with back pain, the Charite artificial disk offers some clear advantages – but also some unanswered questions.
Each year, some 200,000 people undergo spinal fusion surgery for chronic and disabling low back pain. Some back pain sufferers may be candidates for a new device, the Charité artificial disk.
The FDA approved the Charité disk for back pain in late 2004. The disk is made of a plastic core sandwiched between two metal endplates and replaces an actual disk that is removed due to disease or injury, helping to restore the natural distance between two vertebrae. There’s no question that development of the disk opens a new era in surgery for back pain. And artificial disk surgery has a clear advantage over spinal fusion with regard to preserving spinal mobility. However, the disk has its critics -- and some of their observations are sobering.
Not everyone with back pain is a potential candidate for the Charité. The FDA formally approved the disk for people who have degenerative disk disease at one level in the lumbar spine (from L4––S1) and who have experienced no back pain relief after at least six months of non-surgical treatment for low back pain. It is not recommended for people with scoliosis, spondylolisthesis, or degenerative disk disease at more than one level. Overall, of people with back pain who are potential candidates for spinal surgery, 90% would still undergo spinal fusion surgery according to current practice. This may change in the future as surgeons accumulate experience with larger numbers of back pain patients and develop a fuller understanding of the outcomes people have with the Charité disk.
One of the most contentious issues surrounding the Charité disk is the variety of results seen after surgery. The disk was first approved in Europe, and a study conducted there of 53 back pain patients came to the conclusion that, "Proof that long-term results with the disk are at least as good as fusion results is still missing.” This study, published last year, offers the longest perspective of any to date, with a follow-up of 17 years.
In contrast, a second European study of 107 back pain patients with minimum follow-up of 10 years, concluded that the outcomes seen with the disk compared favorably with those typically seen with spinal fusion surgery. In this country, the FDA based its approval on results from a study that found that back pain patients who received the disk did no worse than those who underwent spinal fusion. Follow-up in that study lasted for only 2 years.
If you believe that you’re a candidate for the artificial disk at this time, be sure to ask your surgeon plenty of questions about what your expectations, data on outcomes, and the potential for disk failure. If you want to take a wait-and-see stance, more studies on the Charité disk will be forthcoming. In addition, other artificial disks are being developed for people with back pain and tested in clinical trials, some in head-to-head comparison studies with the Charité disk.
