Kits and methods for use in intraoperative trailing of hip prostheses to determine an appropriate length for the femoral neck component of a prosthetic hip joint, are described. A kit for use in selecting a femoral neck component of an orthopaedic joint prosthesis kit comprises a first (10) and a second (110) broach. Each of the first and second broaches has a neck connection element comprising a projection (12, 112) extending from a proximal surface (14, 114) of the broach, each projection having a length (L). The projection on the first broach has a different length than the projection on the second broach. The kit also includes a trial femoral neck (30) component having a neck connection element in the form of a recess (36) in a distal surface (34). The recess is configured to mate with the projection on each of the first or second broaches such that mating of the trial femoral neck component with the first broach provides an assembly with a first neck length, and the mating of the trial femoral neck component with the second broach provides an assembly with a second neck length.

A system for facilitating arthroplasty procedures includes a robotic device, a reaming tool configured to interface with the robotic device, and a processing circuit communicable with the robotic device. The processing circuit is configured to obtain a surgical plan comprising a first planned position of an implant cup and a second planned position of an implant augment relative to a bone of a patient, determine a planned bone modification configured to prepare the bone to receive the implant cup in the first planned position and the implant augment in the second planned position, generate one or more virtual objects based on the planned bone modification, control the robotic device to constrain the cutting tool with the one or more virtual objects while the cutting tool interfaces with the robotic device and is operated to modify the bone in accordance with the planned bone modification.

An intramedullary stem prosthesis includes a trunnion tapered in a first direction toward a proximal end of the intramedullary stem, and a conical shaft interfacing with the trunnion at a modular taper junction. The conical shaft is tapered in a second direction toward a distal end of the second component and has a proximal portion, a distal portion, and flutes positioned about a longitudinal axis of the conical shaft and extending along an entire length of the conical shaft and terminating at the modular taper junction such that the flutes intersect the modular taper junction. The proximal portion defines a first taper angle, the distal portion defines a second taper angle greater than the first taper angle, and the flutes define a major diameter of the conical shaft. The major diameter tapers at a major diameter taper angle that is constant along the entire length of the conical shaft.

A system and method for improving assembly of a modular prosthesis, particularly a femoral stem. The system and method may include implementation of assembly systems for modular prosthesis having one or more intermediate components between a pair of “end components” such as a stem and a head. Grip structures are provided on non-aligned assembly axes and holders are used for each phase to engage appropriate grip structures for joinder of components having aligned assembly axes.

A connection arrangement (4, 4′) of two components (1, 2) according to the invention has a curved surface portion having a contact point on at least one of these components. The curved surface portion can extend over the entire surface of a groove, for example. The other component has a taper. When assembling the two components before a force is applied, a line connection is created from the 2-contact point connection and when force is applied, the line connection changes through plastic deformation into a strip connection, on the basis of which the two components (1, 2) hold together.

A device, for example a medical implant, and a method of making the same, the device having a metal or metal alloy substrate, for example cobalt chrome, and a diffusion hardened metallic surface, for example a plasma carburized surface, contacting a non-diffusion hardened surface or a diffusion hardened surface having a diffusion hardening species different from that of the opposing surface.

Apparatus and Method for Hip Surgery. An adjustable trial femoral head (400) for assessing anteversion of an acetabular cup relative to a pelvis of a patient are described. The adjustable trial femoral head comprises a spherical body (402) having a bore extending along a polar axis of the spherical body and configured to receive a free end of a femoral neck. A visual alignment guide (420) is mounted on the at least partially spherical body and the orientation of the visual alignment guide relative to the spherical body is adjustable.

An orthopedic prosthesis mold, comprising a first housing including a first cavity therein shaped to form a portion of an orthopedic prosthesis; a second housing coupled to the first housing, the second housing including a second cavity therein shaped to form a portion of an orthopedic prosthesis, wherein the first and second housings are constructed from a material having a first hardness; a first shell element configured to receive at least a portion of the first housing therein; a second shell element configured to receive at least a portion of the first housing therein, wherein the first and second shell elements are constructed from a material having a second hardness greater than the first hardness; and a connection element releasably engageable to the first and second shell elements to prevent separation of the first shell element from the second shell element.

A hip prosthesis head includes: an external element with a convex external surface, and an internal element having a truncated-conical seat; wherein the external element and the internal element are made of different materials; the internal element is coupled in a blind hole of the external element in fit-in coupling mode; the external element has an annular base around the blind hole, and the internal element has a truncated-conical body that is open on the bottom, and an annular base that protrudes radially outwards from a lower edge of the body in order to be in contact with the base of the external element.

An orthopedic prosthesis includes a head which internally accommodates the major motion of a patient, e.g., during walking, thereby reducing wear against a cup or liner. A neck may be utilized which rotates within the distal member about an axis aligned with the major motion of the patient. The orthopedic prosthesis may also include a sacrificial anode, a seal made of natural fibers, and utilize lubricant made of honey.