Artificial disc replacement (ADR), or total disc replacement (TDR), is a type of arthroplasty. It is a surgical procedure in which degenerated intervertebral discs in the spinal column are replaced with artificial devices in the lumbar (lower) or cervical (upper) spine. The procedure is used to treat chronic, severe low back pain and cervical pain resulting from degenerative disc disease. Artificial disc replacement has been developed as an alternative to spinal fusion, with the goal of pain reduction or elimination, while still allowing motion throughout the spine. Another possible benefit is the prevention of premature breakdown in adjacent levels of the spine, a potential risk in fusion surgeries.

Two artificial discs have been approved by the FDA for use in the US: the Charite, manufactured by DePuy for use in the lumbar spine; and the ProDisc, manufactured by Synthes for use in the lumbar spine and cervical spine. They are FDA approved for one-level applications, after clinical trials were said to show patient improvement in motion and pain equivalent to spinal fusion. Two-level disc replacement surgery is considered experimental in the United States, but has been performed in Europe for many years. While these two discs have received FDA approval, some insurance companies in the United States do not cover the surgery, still classifying it as experimental. Effective August 14, 2007, the Centers for Medicare and Medicaid Services (CMS) will not cover Lumbar Artificial Disc Replacement (LADR) for patients over the age of 60, on a national basis. Individual localities regulate the use of the procedure in patients 60 and under. There are several class-action lawsuits pending against the Charite Artificial Disc, and reports of complications with the Pro Disc Artificial Disc implant when used in certain surgical situations.

Artificial disc surgery is still relatively new in the United States, but has been used in Europe for more than 15 years. Now, a Carlsbad California company Aurora Spine Corporation announced that it has received U.S. Food and Drug Administration (FDA) 510(k) clearance for sterile-packed titanium plasma spray coated (TiNano) spinal fusion implants. “This FDA clearance is a major achievement for Aurora Spine. These intervertebral implants are developed to support the entire spine from cervical to lumbar and to accommodate the company’s ZIP -Minimally Invasive Interspinous Fusion System portfolio as well as other fusion products on the market,” said Trent J. Northcutt, President and Chief Executive Officer of the company.

TiNano is Aurora Spine’s unique Titanium Plasma Spray coating on PEEK Interbody implants allowing for bone ingrowth due to its porous structure. TiNano-coated implants provide the advantages of all implant materials, bone-titanium osseo-integration from the titanium coating, as well as the modulus and post-op imaging advantages of PEEK fusion implants. “Patient safety is the most important goal for Aurora Spine and that is the reason for every TiNano coated interbody implant being sterile packed,” said Laszlo Garamszegi, Chief Technology Officer of the company. The FDA clearance includes several interbody fusion devices, including configurations for Anterior Cervical (ACIF), Anterior Lumbar (ALIF), Posterior Lumbar (PLIF), Transforaminal Lumbar (TLIF) and Direct Lateral (DLIF) interbody spacers.

A statement issued by The American Association of Orthopaedic Surgeons (AAOS) recommends caution in using the new devices, as the studies behind their approval were not designed to show their superiority, only that they produced results equivalent to existing treatments. The data shows that artificial disc replacement patients, when compared to spinal fusion patients, have a shorter recuperation period following surgery, but research also shows that spinal fusion patients show no better outcomes than patients undergoing physical therapy. The AAOS also states that disc replacement requires a high level of technical skill for accurate placement, and has a significant level of risk if revision surgery is needed. Members of AAOS and the American Association of Neurological Surgeons joined together as the Association for Ethics in Spine Surgery, formed to raise awareness of the ties between physicians and device manufacturers.