Cervical total disc replacement, part two: Clinical results

Spine arthroplasty is a growing subspecialist area of spinal surgery. There are great opportunities for new materials, devices, and technology to emerge. TDR in the cervical spine offers the opportunity to preserve functional motion and maintain balance. It is postulated that arthroplasty may reduce adjacent-level disease more than traditional surgical treatment methods. The other advantages to this surgical option are immediate implant stability, no complications due to nonunion, and no need for graft harvesting. The Bryan Cervical Disc is a metal-on-polymer implant with some elastic properties and a relatively mobile center of rotation. The Bristol Disc is a semiconstrained metal-on-metal prosthesis allowing AP translation motion of up to 2 mm. The ProDisc-C is a semiconstrained metal-polyethylene design allowing pure rotary motion that may stress the facet joints. Although there are no long-term data available yet, these three cervical prostheses appear promising in the nonfusion treatment of cervical degenerative disc disease.