Spine surgeons at Washington University School of Medicine in St. Louis and other U.S. centres are finding that artificial disc replacement is just as good as, and often better than spinal fusion surgery.
The two procedures are performed on patients with cervical disc damage but presently artificial discs are not an option for patients with arthritis or disc disease at multiple levels in the spine.
Researchers report that patients who had an artificial disc lost less motion in the neck and recovered faster than those who had disc removal and spinal bone fusion.
“Those who received the artificial disc either did equally as well or a little bit better than those who had fusion surgery,” K. Daniel Riew, M.D., a cervical spine surgeon at Washington University Orthopedics and Barnes-Jewish Hospital told Science Daily. “One of the most important findings was that people who got the artificial disc were able to preserve all of their motion.”
Traditionally, the surgery to treat cervical disc disease relieved pressure by removing the offending disc and then fusing the bones of the spine together. Surgery to implant an artificial disc also removes the damaged disc after which the surgeon replaces the disc with an implant.
Patients in the study were randomly assigned to receive either the BRYAN Cervical Disc or standard fusion surgery. Ultimately, 242 received the artificial disc, and 221 had spinal fusion. Improvement following surgery was measured by neck disability index (NDI). Two years following surgery, patients in both groups had improved NDI scores.. Overall, the surgery was rated as successful in 83 percent of the patients who received artificial discs and 73 percent of those who had fusion surgery (230 vs. 194). Part of that difference, Riew says, can be explained by better motion in the neck for those who had artificial discs implanted.
It is known that the neck is always slightly restricted following spinal fusion surgery because bones in the neck have been fused together. The fusion makes it impossible to regain full range of motion. Also, the process of fusion adds slight stress on the spine above and below the fusion site, which can lead to the bone breaking down faster than normal.
The researchers say that the hope with artificial cervical disc replacement is the preserved motion may protect against additional stress at other levels of the spine. In the short term, Riew says most patients receiving artificial disc replacement surgery recovered faster and got back to normal life sooner than fusion surgery patients.