Intervertebral disc arthroplasty
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 disc implants 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. Cervical disc replacement is also an alternative intervention for symptomatic disc herniation with associated arm and hand symptoms. 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. Regulation. United States. Five artificial discs have been approved by the FDA for use in the US. The Charite, manufactured by DePuy, is for use in the lumbar spine. The ProDisc, manufactured by Synthes, is for use in the lumbar spine and cervical spine. The Prestige Cervical disc replacement is manufactured by Medtronic. These three designs 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 was considered experimental in the United States, but has been performed in Europe for many years. This past year The Mobi-c Disc manufactured by LDR was approved in the United States and has FDA approval for one or two level cervical disc reconstruction. In 2015, the FDA approved the artificial disk, manufactured by Aesculap Implant Systems, for the treatment of one-level lumbar degenerative disc disease and developed by Dr. Rolando Garcia and Dr.James B. Yu. While these discs have received FDA approval , some insurance companies in the United States do not cover the surgery, however the trend has been changing. Effective August 14, 2007, the Centers for Medicare & 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. Since Depuy merged with Synthes it is no longer supporting the Charite device in the United States. History. The first reported human clinical effort to replace the disc involved implantation of metallic spheres within the intervertebral space. The devices  and results were not met with acceptance within the spine surgical field though some early surgeons reported good clinical results with improved function and decreased pain. Ferstrom in Sweden, Harmon in the United States and Mckenzie in Canada all reported on their surgical reconstruction of the lumbar disc with various metallic spheres. Artificial disc surgery is still relatively new (over 10 years) in the United States, but has been used in Europe for more than 15 years. In Europe, there are multiple manufacturers and designs available for both lumbar (lower back) and cervical (neck) application. The first device approved for  use in the United States was the Charite artificial disc. Invented at Charite University Hospital in Berlin in the mid-1980s by the East German scientist, two-time Olympic champion in women's artistic gymnastics Karin Büttner-Janz and Kurt Schellnack, the disc received FDA approval in the United States in October 2004, following a four-year clinical trial. One of the worldwide practicing artificial disk replacement is the pioneer drs. Willem Zeegers since 1989. Drs. Willem Zeegers stopped with the Carité and is performing the lumbar Activ L artificial disc replacement (company Aesculap) since 2005. The first surgeon to perform  a Charite artificial disc surgery in the United States was Scott Blumenthal, M.D., a spine surgeon at Texas Back Institute in Plano, Texas. Blumenthal served as principal investigator for the Charite study in the US, after visiting Drs. Willem Zeegers in the Netherlands, who showed him his experience with the Charité artificial disc implantation in the neighties. Drs Zeegers was involved in the evolutionary development of the Activ L instrumentation and Activ L implant design which was designed and invented by Dr. Rolando Garcia from Miami and Dr. James. B Yu. The Active-L seems to be currently the preferred  implanted disc by many doctors throughout the United States in terms of diminished complications post surgery. Dr. Rudolf Bertagnoli helped to develop Pro Disc and its surgical technique in Europe and has taught more than 2,500 surgeons how to perform the procedure. In October 2001, as part of another FDA trial, Jack Zigler, M.D., a spine surgeon at Texas Back Institute in Plano, Texas, performed the first ProDisc-L lumbar ADR in the United States. In 2009 Spinal Kinetics, a leader and innovator in advanced generation artificial disc technology completed the successful implantation of the first patient with the company 's M6-L artificial lumbar disc, and the commencement of the system's initial commercial launch in Europe. This first procedure was completed in Germany by spine surgeon Dr. Karsten Ritter-Lang. Advanced generation viscoelastic discs continue to be used outside the U.S. Recently published data in a study by Chin KR et al. has supported the Axiomed Freedom Cervical Disc replacement implant in single and two level cervical surgeries with two-year outcomes data. Research. There are no systematic reviews of high quality evidence demonstrating the effectiveness of artificial disc replacement. A Norwegian study published in The Spine Journal  in 2017 compared total disc replacement and multidisciplinary rehabilitation with an eight-year follow up. The study was randomized, controlled, multi-center and declares to not being industry funded. 77 patients randomized to surgery and 74 patients randomized to rehabilitation responded at eight-year follow-up. Controversy. The New York Times, January 2008, raised concerns relating to the transparency of research being carried out by investors in Prodisc. 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. 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.