People with painful, unstable necks from degenerative disease have two surgical options when conservative (nonoperative) care fails to help. The first is still considered the gold standard (preferred choice) : anterior cervical discectomy and fusion or ACDF. The second is a total disc arthroplasty or disc replacement. Disc implants have been around for about 10 years now, so we are starting to get some study results with long-term outcomes.
There are several reasons why surgeons even started looking for an alternative treatment approach to replace ACDF. ACDF had been around since the 1950s. More than half a century of data showed that despite improvements in the procedure, patients still had problems.
Increased pressure on the discs and degenerative disease (called adjacent segment degeneration or ASD) on either side of the fusion site were common. Patients ended up having a second surgery more often than expected.
Other problems developed such as stiffness, nonunion of the bone, and broken hardware (plates, screws, pins) used to aid the fusion process. Complications of the surgery also included difficulty swallowing or speaking due to nerve damage.
In the early part of the 21st century (2002), European surgeons started using cervical arthroplasty devices. A year later, the United States Food and Drug Administration (FDA) approved the use of these implants on a trial basis. Three separate implants are now available on the market: the Bryan Cervical Disc System, the Prestige-ST Cervical Disc, and the ProDisc-C.
In this report, the five-year results are provided for patients who were in a two-part study using the ProDisc-C implant. Spine surgeons from 13 different centers randomly placed patients with single-level painful disc degeneration into one of two groups. Group one had the anterior cervical discectomy and fusion (ACDF) and group two received the disc implant. The first report came out after two years. This is the five-year report.
At the end of two years, it was reported that the ProDisc-C implant was equal to cervical (neck) fusion in terms of pain relief and function. Now after five years, we see that patients in both groups continue to report high levels of satisfaction. There have been no failures of the ProDisc-C implants so far.
The two significant findings showing the disc implant superior to fusion include: 1) patients with the ProDisc-C have less neck pain (less intense and less often) compared with patients in the fusion group and 2) the reoperation rate is lower among patients with the implant. All other measures (e.g., complications, failures, X-ray results of bone bridging) were equal between the two groups.
The authors conclude that the ProDisc-C implant provides just as good, if not better, results compared with the “gold standard” of spine fusion. Certainly, the disc implant group did no worse than the fusion group.
The surgeons say they expect in time that the value and benefit of disc replacement will be proven. They predict better outcomes than with ACDF and better motion with less chance of developing adjacent segment disease. And the risk of reoperation will remain significantly lower compared with neck fusion.