Artificial Disc Could Be Future of Back Surgery
Implants seem to help patients in early trials
TUESDAY, Feb. 12, 2002 (HealthDayNews) -- Just four months after surgery, the first American recipient of a ProDisc artificial spinal disc tore apart her old bathroom with a hammer and a chisel, and she can almost touch her toes with her fingers.
You can't run out and sign up for an implant just yet, however.
Kari Smith, 39, of Coppell, Texas, was participating in an U.S. Food and Drug Administration (FDA) trial to see whether the prosthesis, already available in Europe, will fly in this country. Her procedure was performed by surgeons from the Texas Back Institute, one of 10 centers involved in the study. If the FDA approves the implant, it could be commercially available by 2004.
The ProDisc is not the first artificial disc to be tried in the United States. Beth Israel Medical Center's Spine Institute in New York City just finished a separate trial for the SBIII Charité disc and has handed its data over to the FDA for evaluation.
And although it may be premature to declare this the future of back surgery, experts say disc implants look promising.
"The results are certainly encouraging in that this may be the answer to certain situations," says Dr. Andrew Casden, associate director of the Spine Institute at Beth Israel.
Artificial discs would work primarily with degenerative disc disease, where wear-and-tear on a disc causes chronic low back pain, Casden says. The typical treatment, involving surgery that fuses segments of the spine together, has short-term success. Patients often end up in pain again two or three years later and have to go through more surgery.
"It's an interim treatment," explains Dr. Ralph F. Rashbaum, medical director at the Texas Back Institute and one of the surgeons involved in the ProDisc trial. "After a period of time, the patient does well only to fall apart again. Then you fuse another segment."
The purpose of the current trials are to determine whether disc implants could replace fusion as the primary treatment for degenerative disc disease.
"The necessity for an artificial disc arises out of the need to do something other than fusion surgery," says Rashbaum. "If you look at it historically, this has taken exactly the same track as knee replacement and hip replacement. It's gone from hip or knee fusion to replacement. What we're looking for now is a mechanical answer."
"The idea is to maintain motion and take away pain," adds Casden. "We're preserving motion, and sparing the discs below and above from extra strain."
The artificial disc consists of three parts: cobalt-chrome alloy endplates and a polyethylene inlay. The devices have been in use in Europe for 14 years, and appear to be going strong.
Some artificial discs could be available within a year or so, depending on the FDA's response to the trials. Even if approved, both the ProDisc and SBIII Charité could only be implanted in patients who have one or two problematic discs.