TDR has been developed as an alternative to spinal fusion, with the goal of pain reduction or elimination, while still allowing motion throughout the spine.
[1] Another possible benefit is the prevention of premature breakdown in adjacent levels of the spine, a potential risk in fusion surgeries.
[2] Recent studies have shown a strong correlation between providing motion in the spine and avoiding adjacent segment degeneration.
FDA approvals for devices are for one- or two-level use and at specific levels in the cervical or lumbar spine.
Effective August 14, 2007, the Centers for Medicare & Medicaid Services (CMS) does not cover, on a national basis, Lumbar Artificial Disc Replacement (LADR) for patients over the age of 60.
Fernström balls, used in approximately 250 patients, created segmental hypermobility and demonstrated a marked tendency to settle into the vertebral endplates.
Designs patented at that time combined metal, ceramic, or other types of elastic bearings with components made of silicone composites, rubber, polyurethane, plastics, or fluid-filled membranes.
[18] The first design with wide clinical adoption was the Charité disc replacement, designed by East German scientists: two-time Olympic champion in women's artistic gymnastics Karin Büttner-Janz and Kurt Schellnack, a doctor, engineer, and professor—both of whom were affiliated with the Charité Center for Musculoskeletal Surgery at the Medical University of Berlin[2].
First implanted in 1984, the disc had a biconvex polyethylene nucleus within a radiopaque metal ring that interfaced with two cobalt-chromium-molybdenum alloy endplates, which were coated with calcium phosphate.
Designed by French orthopedic spine surgeon Thiery Marnay, M.D., in the late 1980s, early implantations of the prodisc device began in 1990, with a 7-11 year follow-up published in 2005.
The US FDA requires manufacturers to conduct clinical studies to assess the safety and efficacy of disc replacements before obtaining approval to market the devices in the United States.
[19][20] All prospective, randomized clinical studies that have been run in the United States have shown lumbar and cervical disc replacements to provide faster recovery, better long-term patient satisfaction, and fewer incidents of adjacent segment degeneration than comparative spinal fusion options.