Artificial Spinal Disk Superior to Fusion for Treating Degenerative Disk Disease

Abstract

THE PLACEMENT OF AN ARTIFICIAL intervertebral disk can provide better functional results than spinal fusion in treating select patients with discogenic pain and spine instability, according to findings recently presented at the North American Spine Society’s annual meeting, in Seattle. The device, called the ProDisc-L (Synthes Spine Inc, West Chester, Penn), was approved by the US Food and Drug Administration (FDA) in August for the treatment of pain associated with degenerative disk disease. Although artificial disks for total disk replacement surgery have been commercially available in markets outside the United States since 1990, the ProDisc is only the second artificial disk to obtain FDA clearance, preceded by the 2004 approval of the Charite Artificial Disc (DePuy Spine Inc, a Raynham, Mass– based subsidiary of Johnson & Johnson). However, trial findings that were the basis for approving the Charite disk showed only that outcomes of patients treated with the device were no worse than those of patients who had undergone standard spinal fusion. Unlike the Charite disk, which has a free-floating central core, the ProDisc is a semiconstrained prosthesis intended to lend added stability and minimize device migration and subsidence. “The ProDisc artificial implant is the first motion-sparing disk implant ever shown to be superior to fusion,” said Rick B. Delamarter, MD, medical director of the Spine Institute at St John’s Health Center in Los Angeles. Delamarter, an independent researcher with no financial ties to the manufacturer of the ProDisc-L artificial disk, presented the trial findings, which were the basis for the FDA’s approval of the device. “There will always be a role for fusion to treat problems of spinal deformity, severe facet arthritis, and instability, but the pendulum is now shifting to nonfusion technology,” added Delamarter.