A radial head prosthesis for implantation in a distal radius. The implant includes a head portion and a stem portion. The stem portion has a cylindrical shaft and tapered tip. The head portion includes a recess for engagement with the stem portion. The head portion includes a first bearing surface for articulation with a humerus, and a second bearing surface for articulation with an ulna. The second bearing surface includes at least one concave and one convex portion immediately adjacent one another.

This invention improves upon prior art total disc replacements (TDRs) by more closely replicating the kinematics of a natural disc. The preferred embodiments feature two or more fixed centers of rotation (CORs) and an optional variable COR (VCOR) as the artificial disk replacement (ADR) translates from a fixed posterior COR that lies posterior to the COR of the TDR to facilitate normal disc motion. The use of two or more CORs allows more flexion and more extension than permitted by the facet joints and the artificial facet (AF). AF joint-like components may also be incorporated into the design to restrict excessive translation, rotation, and/or lateral bending.

An implant for use in a spine includes a body and a plurality of structural members. The plurality of structural members includes outer members that are arranged to contact a vertebra upon implantation and support members that provide reinforcement and stability to the outer members. The outer members may have sections with a generalized helical geometry. The generalized helical geometry provides distal and proximal outwardly facing surface regions and creates a series of protected fusion zones along the superior and inferior surfaces of the implant to foster adjacent bone growth.

A dynamic intervertebral spacer includes a ring which is split on an anterior portion. A posterior portion of the ring acts as a torsion spring. After implantation, the ring is able to act as a spring between superior and inferior vertebral bodies, thus allowing dynamic bone growth in fusion procedures.

An attachment device for cranioplasty may have a body defined from a sheet material and may include a first connection end having at least a first connection hole configured to cooperate with a fastener to anchor the attachment device to a bone flap or prosthesis covering at least part of the opening in the skull. A second connection end has at least a second connection hole configured to cooperate with a fastener to anchor the attachment device to a skull adjacent to an opening in the skull. A frame portion extends from the first connection end. A coil portion may be between the frame portion and the second connection end, the coil portion having struts configured for deforming in flexion, and webs between the struts configured for deforming in torsion. The frame portion is configured to be located over a periphery of the opening in the skull to block inward movement. The coil portion enables an out-of-plane deformation of the attachment device for the first connection end to move out of a neutral plane with the second connection end.

A bone implant includes at least one bone-engaging surface designed to mate with an implant-engaging surface of a bone. In the preferred embodiment, the bone-engaging surface of the implant includes a wave pattern comprising at least one peak extending in a proximal direction or at least one valley extending in a distal direction. The implant-engaging surface of the bone also includes a matching wave pattern having at least one peak and valley. Upon mating the engaging surfaces, a bone-implant interface may be created wherein the peaks and valleys of the wave patterns are aligned. As a result, there is good surface contact area at the bone-implant interface which helps prevent loosening or rotating of the implant.

A dynamic intervertebral spacer includes a ring which is split on an anterior portion. A posterior portion of the ring acts as a torsion spring. After implantation, the ring is able to act as a spring between superior and inferior vertebral bodies, thus allowing dynamic bone growth in fusion procedures.

Technologies are generally provided for devices and methods for use in bone fixation, bone fusion and/or bone stabilization. In various embodiments, the devices and methods relate to a bone stabilization having a first end, second end and a bridge connecting the first and second ends. The first end has a bone engagement feature and may be fused to bone over time without the use of osteogenic materials.

Anchoring devices for rachidian implants, implants, surgical instruments, and surgical systems and methods are disclosed. In some embodiments, an anchor comprises a stiff plate with a longitudinal axis, configured for penetration of its anterior end into a vertebral surface while its posterior end remains engaged with the implant. An implant may include a locking mechanism for the anchor. An anchor may include an abutment configured to abut a complementary abutment of an implant. In some configurations, inserting an anchor in a passage of an implant may displace a locking mechanism, which may resile and lock the anchor in the implant with complementary abutments of the anchor and implant abutting.

A radial head prosthesis for implantation in a distal radius. The implant includes a head portion and a stem portion. The stem portion has a cylindrical shaft and tapered tip. The head portion includes a recess for engagement with the stem portion. The head portion includes a first bearing surface for articulation with a humerus, and a second bearing surface for articulation with an ulna. The second bearing surface includes at least one concave and one convex portion immediately adjacent one another.