Spacerless artificial disc replacements (ADR) are disclosed. One preferred embodiment includes two saddle-shaped components to facilitate more normal spinal flexion, extension, and lateral bending while limit axial rotation, thereby protecting the facet joints and the annulus fibrosus (AF). Either or both of the superior and inferior components are made of a hard material such as chrome cobalt, titanium, or a ceramic including alumina, zirconia, or calcium phosphate. The articulating surfaces of the ADR are also preferably highly polished to reduce friction between the components. Metals, alloys or other materials with shape-memory characteristics may also prove beneficial.

An implant (30) for a mammalian bone joint (3) for spacing a first bone (2) of the joint from a second bone (1) of the joint while allowing translational movement of the second bone in relation to the first bone is described. The implant comprises (a) a distal part (31) configured for intramedullary engagement with an end of the second bone, (b) a proximal part (34) having a platform (15) configured for non-engaging abutment of an end of the first bone and translational movement thereon, and (c) an articulating coupling (10, 16) provided between the distal and proximal ends allowing controlled articulation of the first and second bones. The bone-abutting platform is shaped to conform to and translate upon the end of the first bone. A kit for assembly to form the implant of the invention, and the use of the implant to treat osteoarthritis in a bone joint, are also described.

Apparatus and methods for preparing a disc space and inserting an intervertebral disc implant therein are disclosed. Among the various instruments disclosed are a midline marker, a reference pin drill and insertion guide, a pin drill guide, a chisel guide, a sizer, a serrated broach, an implant dispenser, and an implant insertion tool. Methods of utilizing these tools are also disclosed.

Instrumentation for implanting a cervical disc replacement device includes cervical disc replacement trials for determining the appropriate size of replacement device to be implanted, an insertion plate for maintaining the elements of the replacement device in fixed relation to one another for simultaneous manipulation, an insertion handle for attachment to the insertion plate for manipulation of the elements, an insertion pusher for releasing the insertion handle from the insertion plate, a drill guide that cooperates with the insertion plate to guide the drilling of tap holes for bone screws to be placed through bone screw holes in the flanges of the replacement device, clips that are applied to the flanges after placement of the bone screws to resist screw backout, and a clip applicator for applying the clips to the flanges.

An ankle arthroplasty system may have a talar prosthesis and a tibial prosthesis, each of which has an articular surface and a bone engagement surface. Each bone engagement surface may have an anterior-posterior curvature and a medial-lateral curvature with a convex shape. A burr with a rotatable cutting element may be used to form a prepared surface on the talus or the tibia to receive the corresponding prosthesis. A cutting guide may be used to guide motion of the burr; the cutting guide may include a base and an arm movably coupled to the base. One of the base and the arm may have a guide surface, and the other may have a follower that slides along the guide surface to constrain motion of the burr such that the prepared surface has at least one concave curvature and one convex curvature.

An ankle arthroplasty system may have a talar prosthesis and a tibial prosthesis, each of which has an articular surface and a bone engagement surface. Each bone engagement surface may have an anterior-posterior curvature and a medial-lateral curvature with a convex shape. A burr with a rotatable cutting element may be used to form a prepared surface on the talus or the tibia to receive the corresponding prosthesis. A cutting guide may be used to guide motion of the burr; the cutting guide may include a base and an arm movably coupled to the base. One of the base and the arm may have a guide surface, and the other may have a follower that slides along the guide surface to constrain motion of the burr such that the prepared surface has at least one concave curvature and one convex curvature.

An ankle arthroplasty system may have a talar prosthesis and a tibial prosthesis, each of which has an articular surface and a bone engagement surface. Each bone engagement surface may have an anterior-posterior curvature and a medial-lateral curvature with a convex shape. A burr with a rotatable cutting element may be used to form a prepared surface on the talus or the tibia to receive the corresponding prosthesis. A cutting guide may be used to guide motion of the burr; the cutting guide may include a base and an arm movably coupled to the base. One of the base and the arm may have a guide surface, and the other may have a follower that slides along the guide surface to constrain motion of the burr such that the prepared surface has at least one concave curvature and one convex curvature.

A method of inserting an intervertebral disc implant into a disc space includes accessing a spinal segment having a first vertebral body, a second vertebral body and a disc space between the first and second vertebral bodies. The method includes securing a first pin to the first vertebral body and a second pin to the second vertebral body, using the first and second pins for distracting the disc space, and providing an inserter holding the intervertebral disc implant. The method also desirably includes engaging the inserter with the first and second pins, and advancing the inserter toward the disc space for inserting the intervertebral disc implant into the disc space, whereby the first and second pins align and guide the inserter toward the disc space.

Devices and methods are disclosed for joint replacement.

An ankle arthroplasty system may have a talar prosthesis and a tibial prosthesis, each of which has an articular surface and a bone engagement surface. Each bone engagement surface may have an anterior-posterior curvature and a medial-lateral curvature with a convex shape. A burr with a rotatable cutting element may be used to form a prepared surface on the talus or the tibia to receive the corresponding prosthesis. A cutting guide may be used to guide motion of the burr; the cutting guide may include a base and an arm movably coupled to the base. One of the base and the arm may have a guide surface, and the other may have a follower that slides along the guide surface to constrain motion of the burr such that the prepared surface has at least one concave curvature and one convex curvature.