A spinal implant for intervertebral disc replacement. The implant is formed from two hemicylindrical elements, each engaging one of an adjacent pair of vertebrae. An articulating ball-and-socket joint between the two elements resists compression and lateral movement between the vertebrae, but allows pivotal movement, thereby preserving mobility. Fusion chambers are provided for allowing bone ingrowth to fuse the elements to the vertebrae. Biocompatible, bioreabsorbable struts, shims, fillers and/or end caps are provided for temporary stabilization of the first and second hemicylindrical elements. Bone chips removed from the vertebrae during implantation or bone growth stimulators can be inserted into the fusion chamber or otherwise applied to the implant to enhance bone ingrowth.
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.
A device for connecting vertebrae of the vertebral or spinal column through an implant to be arranged between the vertebrae. The implant has at least one hollow space and openings to allow bone tissue formed for connecting the vertebrae to grow into the implant. The implant includes a connecting portion to be placed against exposed soft bone tissue and at least one spacer portion protruding from the connecting portion to be placed against hard bone tissue.
A disk prosthesis for cervical vertebrae. The prosthesis includes a spherical cap formed on a first insert, while a spherical cup is formed on a second inset, two inserts made of ceramic material, one of the inserts being mounted on a first plate while the other insert is mounted on a second plate in such a manner that the center of rotation of the joint is substantially centered relative to the edges of the plates, a spherical cup possessing a contact surface area that is not less than that of the spherical cap and being connected via an annular molding to the base of the insert, and a plate provided with the insert having the spherical cap includes an annular setback to leave clearance for the annular molding.
An expandable intervertebral fusion implant includes a pair of semi-cylindrical shells having mating surfaces which resist shifting when the parts are assembled. The cylinder thus formed is placed on a special installation tool, which is first used to place the cylinder in the intervertebral space. Thereafter, the tool is actuated to spread the shells, and a spacer of appropriate size and taper is slid over the tool shaft, and in between the shells to maintain their spacing after the tool is removed. Having spacers of different height and taper allow the surgeon to adapt the implant to various situations.
