A four-component artificial intervertebral disc may provide six degrees of movement: flexion, extension, lateral bending, axial rotation, axial deflection, and anterior/posterior translation. The disc may include a superior endplate, a superior core, an inferior core, and an inferior endplate. The superior endplate may include a concave mating surface, and the inferior endplate may include a spherical mating surface. The superior endplate may roll across the superior core to provide flexion, extension, and lateral bending. The superior endplate may twist or rotate atop the superior core to provide axial rotation, and the superior endplate may slide over the superior core to provide anterior/posterior translation. The superior core may be connected to the inferior core, and the inferior core may be connected to the inferior endplate. The inferior core may be made from a flexible material that may enable the artificial disc to expand or compress vertically.

This shoulder prosthesis glenoid component (2) has on one of its faces an articulation surface (S.sub.A) adapted to cooperate with a humeral head and having, on an opposite face (S.sub.G) adapted to be immobilized on the glenoid cavity (G) of a shoulder, a keel (4) for anchoring it in the glenoid cavity (G). This keel (4) comprises a body (5) that extends from the opposite face (S.sub.G). The keel (4) comprises at least one fin (6) projecting from the body (5) 2 which runs over at least a part of the perimeter of the body (5).

Systems and methods for modifying a shoulder joint configuration exhibiting wear that take into account resultant of forces responsible for the wear of the glenoid surface from geometric characteristics of wear.

Disclosed are orthopedic implant kits. One disclosed kit comprises an implant having a joint head portion, the joint head portion having a generally convex distal surface and generally concave proximal surface, the implant comprising a post portion protruding proximally from the proximal surface, the post portion having a dorsal surface and a ventral surface (which is a plantar surface in the case of a metatarsal bone) and including a first threaded aperture extending therebetween, and a bone screw. The bone screw has a threaded shaft complementary to the threaded surface of the post portion and preferably is configured to provide bicortical fixation of the implant.

Low profile offset reamers include reamer heads with outer diameters that are substantially greater than the overall height of the working portion, which includes the reamer head, a reamer coupler, and a working tip that supports the reamer head and reamer coupler. The overall height is measured parallel to the rotational axis of the reamer head, and the outer diameter is measured perpendicular to the rotational axis.

An expanded spinal fusion cage is provided and includes: an outer frame; a sliding block set with a middle sliding block located within the outer frame, and the middle sliding block is located between two outer sliding blocks; a screw rod penetrating through and combined with the outer frame, and the screw rod is screwed with the middle sliding block, so that the middle sliding block is moved in translation in the outer frame and simultaneously expands the two outer sliding blocks by rotating the screw rod; two curved surface elements located outside the outer frame and combined with the two outer sliding blocks respectively, each of the curved surface elements has a wing plate; and two vertebral arch screws penetrating through and combined with the two wing plates.

An intervertebral implant component of an intervertebral implant includes an outer surface for engaging an adjacent vertebra and an inner surface. A keel extends from the outer surface and is designed to be disposed in a slot provided in the adjacent vertebra. This keel extends in a plane which is non-perpendicular to the outer surface; and preferably there are two of the keels extending from the outer surface which are preferably offset laterally from one another. In another embodiment, an anterior shelf is provided at an anterior end of the outer surface, and this anterior shelf extends vertically away from the inner surface in order to help prevent bone growth from the adjacent vertebra towards the inner surface. Further in accordance with disclosed embodiments, various materials, shapes and forms of construction of the component and/or keel provide various benefits.

An intervertebral disc is provided having an upper plate, a lower plate, and a core. The upper and lower plates include outer vertebral body contacting surfaces which are provided with attachment enhancing features to ensure bone integration. The attachment enhancing features shown include one or more fins, serrations and teeth. An opposite surface of the plates from the vertebral body contacting surfaces is formed with a recess which serves as a bearing surface for the core. In order to form an intervertebral disc with a lower disc height, at least one of the recesses is provided opposite a corresponding dome shaped portion on the vertebral body contacting surfaces. This allows the plates to be formed with a thinner profile for a smaller overall disc height. In addition to providing a lower overall height to the artificial disc, the dome shaped portion of the plates also provides a more anatomically shaped outer vertebral body contacting surface.

The disclosure provides an intervertebral disc and related methods. An upper plate includes an upper vertebra contacting portion and a lower bearing surface portion. The upper vertebra contacting portion includes a convex central portion, and a fin or anchoring element with a transverse hole therethrough. A lower plate has a lower vertebra contacting surface and an upper bearing surface. The lower vertebra contacting surface of the lower plate has a convex central portion. The upper bearing surface has a concavity disposed opposite the convex central portion and wherein the convex central portion and the concavity have nesting curvatures. A core positioned between the upper and lower plates has rigid upper and lower convex surfaces configured to slide and translate over the bearing surfaces of the upper and lower plates.

One embodiment of the present disclosure relates to a glenoid implant with a body and a keel. The body includes an articulation surface and a bone facing surface, and the keel has a depth that extends from the bone facing surface to a free end of the keel. The keel has a first length and a first width, both measured in a plane perpendicular to a direction of the depth. The first length is measured perpendicular to the first width and is defined by a first distance from an inferior end of the keel to a superior end of the keel. The first width is measured at a first location adjacent to the inferior end, and the keel has a width dimension along a first portion of the keel from the first location to the superior end that tapers from the first location toward the superior end.