A shoulder assembly is provided which includes a base member including a collar; a helical structure extending from the collar in a distal direction; and a first pathway projecting distally of the collar and through the helical structure adjacent to an inner periphery thereof, the first pathway being generally transverse to the helical structure and extending in a space between successive portions of the helical structure; and a locking device comprising a proximal support and a first arm projecting distally of the proximal support, the first arm configured to be disposed in the first pathway projecting distally of the collar when the proximal support is disposed adjacent to the collar; where the first arm is disposed through bone in the space between successive portions of the helical structure when the shoulder assembly is implanted.

A two piece humeral component for use in joint arthroplasty which is adapted to be implanted into a joint and engaged by a socket component of the joint. The joint component includes a body having a first articulating surface and a second medial surface opposite the first articulating surface. The first articulating surface is adapted to be engaged by the socket and the second medial surface is adapted to be secured to mounting portion. The mounting portion has a first surface and a second medial surface. The first surface is adapted to be fixably engaged to the second mounting portion of the humeral component. The second medial surface is adapted to be secured to the humerus. A peg which has a first end adapted to engage a cavity found in the humerus is disposed on the mounting portion's second medial surface.

The present invention relates to an articular joint replacement system. The system has first and second components. Each component has a tapered head piece for covering the end of a bone and for acting as an articular surface, an integrally formed screw stem having a length sufficient to extend into the medullary canal, and inwardly angled bone grips affixed to the underside of the head piece to allow solid fixation to the bone by compression press fit. The head piece of the first component is provided with a shaped exterior surface which complements the shaped exterior surface of the head piece of the second component and which allows motion in three planes.

Surgically installed prostheses replace either the caudal portion of a natural facet joint, the cephalad portion of a natural facet joint, or both. The prostheses are readily attached to the pedicles of a vertebral body and support at least one element that defines an artificial facet joint structure. The caudal facet joint structure is sized and located to articulate with the cephalad facet joint structure. Together, the prostheses form a total facet replacement system. The system is suitable for use in virtually all levels of the spine.

A shoulder assembly is provided which includes a base member including a collar; a helical structure extending from the collar in a distal direction; and a first pathway projecting distally of the collar and through the helical structure adjacent to an inner periphery thereof, the first pathway being generally transverse to the helical structure and extending in a space between successive portions of the helical structure; and a locking device comprising a proximal support and a first arm projecting distally of the proximal support, the first arm configured to be disposed in the first pathway projecting distally of the collar when the proximal support is disposed adjacent to the collar; where the first arm is disposed through bone in the space between successive portions of the helical structure when the shoulder assembly is implanted.

The present invention relates to an articular joint replacement system. The system has first and second components. Each component has a tapered head piece for covering the end of a bone and for acting as an articular surface, an integrally formed screw stem having a length sufficient to extend into the medullary canal, and inwardly angled bone grips affixed to the underside of the head piece to allow solid fixation to the bone by compression press fit. The head piece of the first component is provided with a shaped exterior surface which complements the shaped exterior surface of the head piece of the second component and which allows motion in three planes.

An expandable intervertebral spacer includes a body, a proximal end, and a distal end. The body includes quadrants that form a substantially cylindrical shape in a first configuration and a substantially cuboidal shape in a second configuration. Each quadrant includes a ramp portion with a ramp and a landing and a sliding portion with a sliding side and a foot. The ramp portion of a first quadrant engages the sliding portion of a second quadrant. The proximal end and the distal end couple with the plurality of quadrants and transfer an actuating force to expand the body from the first configuration to the second configuration.

Provided is a bone joining device suitable for joining a first bone piece to a second bone piece. Also provided is a method of j oining a first bone piece with a second bone piece in a living mammal. The method comprises inserting the above bone joining device between the first bone piece and the second bone piece.

A prosthesis replaces all or a portion of a natural facet joint on a vertebral body. The prosthesis has a prosthesis body accommodating fixation to the vertebral body at or near a pedicle and without support by a lamina. The prosthesis body has a fastening element installed within the vertebral body at or near a pedicle. The prosthesis further has an artificial facet joint structure carried by the prosthesis body at a location spaced from the fastening element. The artificial facet joint structure is adapted and configured to replace all or a portion of a natural facet joint.

Provided is a bone joining device suitable for joining a first bone piece to a second bone piece. Also provided is a method of joining a first bone piece with a second bone piece in a living mammal. The method comprises inserting the above bone joining device between the first bone piece and the second bone piece.