US Patent 7282063 Artificial disc spinal surgical prosthesis

A spinal surgical prosthesis such as an artificial disc having a pair of upper and lower plate members, a flexible disc interposes therebetween and a rigid collar made of a bio-compatible and bio-resorbable material surrounding the flexible disc between the upper and lower plate members. Prior to the resorption of the collar, the collar serves to provide stability to the flexible disc for enhancing osteo-integration of the prosthesis with adjacent vertebrae. Subsequent to the resorption of the rigid collar, the flexible disc provides flexibility and compressibility while maintaining the proper inter disc space and lordosis or kyphosis between adjacent vertebrae.