A system for replacing a portion of an articular surface including providing an implant site and installing an implant into the implant site. The implant site includes a first and a second excision site which at least partially intersect with one another. Each of the first and second excision sites are formed by providing a respective axis and excising a portion of the articular surface relative to the respective axes.

A separate nub component between the plate and an intervertebral fusion cage, wherein the nub is attached to the plate. The nub lessens the undesired pivotal movement of the plate. It is believed that when the nub fits snugly between the endplates of the adjacent vertebral bodies, it acts as a stop against the undesired pivotal movement of the plate.

Described here are deformable, monolithic, stabilization implants suitable for use within bone and between bones to fuse vertebral bodies, to repair herniated discs, or to repair spinal compression fractures. The implants are introduced into a chosen site at a first, smaller height and then plastically deformed to achieve a second, but unique, pre-selected, larger height. Variations of the device provide one or more specific larger heights. The devices are suitable as intervertebral spinal fusion implants for the immobilization of adjacent vertebral bodies. Methods of and instruments for deployment of the implants are also described. Also described are variations of the device suitable as sizing instruments.

A modular acetabular cup assembly for use with multiple bearing liners is disclosed. The acetabular cup assembly includes a shell having a tapered inner wall and two circumferential grooves. The shell may be used with polyethylene, ceramic, metal, and other types of liners.

A separate nub component between the plate and an intervertebral fusion cage, wherein the nub is attached to the plate. The nub lessens the undesired pivotal movement of the plate. It is believed that when the nub fits snugly between the endplates of the adjacent vertebral bodies, it acts as a stop against the undesired pivotal movement of the plate.

A fusion cage has a first component that defines an outside surface that is configured to engage a vertebral endplate, and an interior surface. The fusion cage has a second component that defines first and second opposed surfaces. One of the first and second opposed surfaces can mate with the interior surface of the first component. The fusion cage can include vertical and lateral throughholes adapted to enhance fusion.

A modular acetabular cup assembly for use with multiple bearing liners is disclosed. The acetabular cup assembly includes a shell having a tapered inner wall and two circumferential grooves. The shell may be used with polyethylene, ceramic, metal, and other types of liners.

A modular acetabular cup assembly for use with multiple bearing liners is disclosed. The acetabular cup assembly includes a shell having a tapered inner wall and two circumferential grooves. The shell may be used with polyethylene, ceramic, metal, and other types of liners.

A fusion cage has a first component that defines an outside surface that is configured to engage a vertebral endplate, and an interior surface. The fusion cage has a second component that defines first and second opposed surfaces. One of the first and second opposed surfaces can mate with the interior surface of the first component. The fusion cage can include vertical and lateral throughholes adapted to enhance fusion.

A separate nub component between the plate and an intervertebral fusion cage, wherein the nub is attached to the plate. The nub lessens the undesired pivotal movement of the plate. It is believed that when the nub fits snugly between the endplates of the adjacent vertebral bodies, it acts as a stop against the undesired pivotal movement of the plate.