For cervical disc radiculopathy, is a motion preserving disc superior or inferior to traditional fusion?
A research team from the Department of Neurosurgery, St Olavs Hospital, Trondheim University Hospital in Trondheim, Norway designed a rigorous randomly controlled study with five-year follow-up to try to answer that question. Their study, “Effect of Arthroplasty vs Fusion for Patients With Cervical Radiculopathy: A Randomized Clinical Trial,” appears in the August 5, 2021 edition of JAMA Network Open.
Co-author Tonje Okkenhaug Johansen, M.D. explained the objectives of the study to OTW. “Most research done on arthroplasty for cervical radiculopathy has been industry sponsored and unblinded[i]. This is problematic as there is high risk of biased results. We therefore wanted to conduct an independent RCT [randomized controlled trial], the NORCAT [Norwegian Cervical Arthroplasty Trial] study, which blinded both patients and clinicians, to compare efficacy between arthroplasty and fusion. The two-year results found equal and beneficial outcomes for both treatment options, and the aim of the present study was to evaluate the five-year outcomes and reoperation rates.”
The research team collected patient data for Neck Disability Index, arm and neck pain, quality of life, reoperation rates, and adjacent segment disease. The researcher team randomly assigned patients to either arthroplasty or fusion. All patients were blinded as to which treatment they received. The surgical team remained blinded until the nerve root decompression was finished.
A total of 114 patients completed the five-year follow-up. The mean Neck Disability Index score was 45.9 points at baseline and 22.2 points at five years in the arthroplasty group. In the fusion group, the mean Neck Disability Index score was 51.3 points at baseline, and 21.3 points at five years.
Changes in mean Neck Disability Index scores between baseline and five years were statistically significant for arthroplasty (mean change, 24.8) and fusion (mean change, 29.9), but the change in mean Neck Disability Index scores was not significantly different between groups (difference, 5.1 points).
The researchers found no significant differences in changes in arm pain, neck pain, health-related quality of life, patients requiring reoperation (10 patients vs. 8 patients), and adjacent segment disease (0 patients vs. 1 patient) between the arthroplasty and fusion groups.
“The most important results were statistically and clinically significant improvement in all outcome measures for both treatment methods at five years,” said Dr. Johansen to OTW, “and the change in outcome measures between the groups were not statistically different.”
Dr. Johansen, also with the Department of Neuromedicine and Movement Science at the Norwegian University of Science and Technology in Trondheim, commented to OTW, “We conclude that arthroplasty and fusion are equally good treatment options for cervical radiculopathy both in the short and long term. The rate of reoperations and adjacent segment disease are also equal. This means that other factors, such as treatment cost to the patient and health care system, length of surgical procedure and surgeons’ preference should be taken into consideration when choosing treatment strategy.”
[i] Editor’s Note: Every motion preserving disc currently being sold in the United States has been tested through the rigorous Food and Drug Administration PMA regulatory pathway, which requires randomized control studies and a minimum of two-year follow-up. In fact, with respect to the Pro-Disc and the Mobi-C cervical arthroplasty implants, more than 10-year RCT follow up data is available and has been published.
