From AANS: Is Disc Arthroplasty Better than Fusion?
By Tricia Rodewald, Marketing Director at Pro-Dex Inc.
In 2002, a study was conducted to determine long-term clinical outcomes in patients undergoing anterior cervical surgery in which a cervical disc (the Prestige from Medtronic Inc.) prosthesis was used to treat single-level degenerative cervical disc disease.
Essentially, the investigational group was comparing the five-year results in patients undergoing disc arthroplasty using the Prestige cervical disc with those obtained in patients undergoing single-level fusion.
The results of this study were published in the Journal of Neurosurgery
and received “Best of the Best” designation for its significance in terms of data and scientific information. Co-author of the paper, J. Kenneth Burkus, M.D., presented the study’s findings at this year’s American Academy of Neurosurgery (AANS) Annual Meeting.
A challenge with anterior cervical discectomy and fusion (ACDF), as noted in a retrospective study (Hilibrand AS, Bohlman HH), is that adjacent segment degeneration occurs and is accelerated by close to 3 percent per year in patients who’ve had ACDF.
Above: Medtronic's Prestige cervical disc implant.
However, fusions are still the preferred method by most surgeons (Side note: one panel session attendee shared that when he informally asked a group of neurosurgeons what they would choose if they were faced with degenerative disc disease, 60 percent were in favor of fusion).
So what made this study, and its corresponding paper, the best?
First, Medtronic’s Prestige was the first disc approved by the U.S. Food and Drug Administration (FDA) and the first to report five-year interim data. The paper presented at AANS was the first time that the complete 24-month prestige data was revealed (60-month data is interim-only).
Second, while some areas of comparison were statistically irrelevant, the results showed that, by and large, patients got better, faster with the disc arthroplasty with continued improvement after five years.
As the paper concludes: “Cervical disc arthroplasty has the potential for preserving motion at the operated level while providing biomechanical stability and global neck mobility and may result in a reduction in adjacent segment degeneration … Cervical disc arthroplasty may provide the benefits of neural decompression without placing adjacent motion segments at risk for accelerated degeneration.”
Statistically notable findings from the study:
• Revisions (adjustments or modifications to the original implant): none in the Prestige group, five in the ACDF group.
• Supplemental fixations (such as posterior wiring or plating): zero in the Prestige group, five in the ACDF group.
• Re-operations (any surgical procedure that treats the level but doesn’t remove or modify the implant): four in the Prestige group, two in the ACDF group.
While there are critiques of the study and continued uncertainty about whether cervical disc arthroplasty is a better option than ACDF, the consensus is that this study provides the best data and information in support of arthroplasty. Authors found significant improvements in NDI (Neck Disability Index), SF-36, and pain scores in the arthroplasty group versus the fusion group at certain time points.