The present invention relates to a prosthesis, such as a megaprosthesis, for a joint replacement or any segmental bone deficit. In particular, the present invention relates to a stem for a prosthesis having threads on at least part of an outer surface thereof. A prosthesis, such as a megaprothesis, is also provided. The prosthesis contains the threaded stem and a modular body engaged to the stem. The modular body contains a bone replace segment or a replacement joint, such as replacement knee joint, hip joint, shoulder joint, wrist joint, ankle joint, elbow joint, joints of the hand, joints of the foot, etc.

An implant for therapeutically separating bones of a joint has two endplates each having an opening through the endplate, and at least one ramped surface on a side opposite a bone engaging side. A frame is slideably connected to the endplates to enable the endplates to move relative to each other at an angle with respect to the longitudinal axis of the implant, in sliding connection with the frame. An actuator screw is rotatably connected to the frame. A carriage forms an open area aligned with the openings in the endplates. The openings in the endplates pass through the carriage to form an unimpeded passage from bone to bone of the joint. The carriage has ramps which mate with the ramped surfaces of the endplates, wherein when the carriage is moved by rotation of the actuator screw, the endplates move closer or farther apart.

A tool assembly includes a universal, intervertebral bone fusion spacer for insertion into a disc space between a first vertebral body and a second vertebral body and fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion, and a tool for manipulating and inserting the universal, intervertebral bone fusion spacer into the disc space between the first vertebral body and the second vertebral body to provide fusion of the first vertebral body to the second vertebral body via biological bone fusion and screw fusion.

A unique, universal Zero-Profile Expandable Intervertebral Spacer (ZP-EIS) device for fusion and distraction throughout the entire spine is provided which can be inserted via anterior, anterolateral, lateral, far lateral or posterior surgical approaches dependent on the need and preference. Multiple ZP-EIS embodiments each with unique mechanisms of calibrated expansion are provided. Two of these embodiments incorporate bi-directional fixating transvertebral (BDFT) screws and five other embodiments do not incorporate BDFT screws. A tool for implantation into the intervertebral device and calibrated device expansion is also disclosed.

Stand-alone interbody fusion devices for engagement between adjacent vertebrae. The stand-alone interbody fusion devices may include a spacer and one or more inserts or members coupled to the spacer. The inserts or members may be configured and designed to provide the apertures which are designed to retain bone fasteners, such as screws, and secure the implant to the adjacent vertebrae.

Implant assemblies, systems, and methods for stabilizing a joint between a superior vertebra and an inferior vertebra may include a plate member coupled to an interbody spacer with at least one fastener that extends superiorly or inferiorly from the implant assembly to anchor within a vertebral body and stabilize the joint. Inserters and methods of insertion may also be included to facilitate fixation of various implant assemblies within the intervertebral space of the joint between the superior vertebra and the inferior vertebra.

In some aspects, a device comprising an implant configured for insertion into a portion of human anatomy, and at least one covering coupled to the implant is provided. According to some aspects, the implant comprises one or more protrusions configured to prevent leakage of material and/or to resist displacement of the implant. According to some aspects, the covering is configured to facilitate improved leakage and/or implant displacement prevention.

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.

An acetabular cup prosthesis comprising: an inner cup surface and an outer cup surface, said inner cup surface meeting said outer cup surface at a rim of said cup, wherein said inner cup surface, said outer cup surface or both said inner cup surface and said outer cup surface comprises an engagement formation located proximal to said rim, said engagement formation extending around at least a portion of the circumference of the cup; and a Sip member comprising an engagement formation configured to cooperate with the engagement formation of the cup.

An expandable assembly for insertion into an intervertebral space is presented. The assembly, in particular aspects, includes an elongate body comprising an upper portion and a lower portion. The assembly may include an expander that is sized and shaped for insertion between the upper portion and lower portion, thereby selectively expanding the upper portion away from the lower portion. The elongate body may also include one or more bone graft windows.