A prosthetic hip joint implant comprises an acetabular liner having an acetabular liner inner surface and defining an acetabular recess, and a femoral component comprising a head having a head outer surface and defining a head recess, a shaft having a shaft proximal end and a shaft distal end disposed within the head recess, and a covering disposed on and fixedly secured to the head outer surface, the shaft distal end, head, and covering disposed within the acetabular liner recess such that the covering is in continuous contact with the acetabular liner inner surface. Polyaxial movement of the shaft distal end produces movement of the covering along the acetabular liner inner surface within the acetabular liner recess without producing relative movement between the covering and the head.

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 system and method for improving mechanical assemblies, such as prosthetic implants, intended to be installed in living tissue such as bone. Force-imparting devices are adapted and may include angularity, which may be introduced with specialized additive manufacturing, which may impart congruent cross-sections while providing variable stiffness. In some cases, the variable stiffness may be “stretchy” in a longitudinal direction and “rigid” in a radial directional which may provide an assembly bias. Additive manufacturing may allow the material of a prosthesis to be varied (e.g., density/porosity) to create variable stiffness over a length.

A ceramic component to be securely connected to an additional component in force-locked manner. A joint prosthesis comprising a ceramic sphere (1), a metallic sleeve (2) and a base plate (3) with a cylindrical projection. The connection between the ceramic sphere and the base plate or shaft (7) is secured by a screw (6).

In an artificial joint that includes a head assembly attached by taper fit to a proximal portion of a surgically implanted stem, it may become necessary to surgically remove the head assembly. A puller can simultaneously apply a force distally to a non-peripheral portion of a proximal side of the head assembly and proximally to several locations spaced apart around a circumference of the distal side of the head assembly. In some examples, the proximal side of the head assembly includes a plug disposed at the non-peripheral portion. The puller can force the plug into contact with the proximal end of the stem, then apply the distal force through the plug to the stem. In other examples lacking a plug, the non-peripheral portion of the head can deform or break in response to the applied distal force, so that the distal force can apply to the stem.

There is provided an acetabular cup liner for a total hip replacement (THR) prosthesis comprising an inner surface with a hemispherical portion having a radius of curvature. The hemispherical portion is disposed about a centerline and it intersects a hemisphere plane perpendicular to the centerline so that the intersection of the hemispherical portion and the plane define a circle having a radius equal to the radius of curvature. The liner further comprises a capture portion continuous with the hemispherical portion that has the same radius of curvature as the hemispherical portion and connects with the hemispherical portion at the hemispherical plane along a first arc of the circle on the plane, and extends a first distance out of the plane. The liner further comprises an insertion portion continuous with the hemispherical portion. The insertion region is connected with the hemispherical portion along a second arc of the circle on the plane. The distance from the centerline to the insertion portion is greater than the radius. The cup liner constrains the femoral ball portion of the THR prosthesis. The femoral ball portion is engaged with the liner by orienting the ball at an angle so that the shoulder portion of the ball aligns with the insertion portion, pressing the ball into the liner, and orienting the ball away from the angle.

An implant suitable for being anchored with the aid of mechanical vibration in an opening provided in bone tissue. The implant is compressible in the direction of a compression axis under local enlargement of a distance between a peripheral implant surface and the compression axis. The implant includes a coupling-in face which serves for coupling a compressing force and the mechanical vibrations into the implant, which coupling-in face is not parallel to the compression axis. The implant also includes a thermoplastic material which, in areas of the local distance enlargement, forms at least a part of the peripheral surface of the implant.

A spacer device for the two-step treatment of prosthesis infections, made from biologically compatible and porous material designed to allow the possibility of adding pharmaceutical products, active and/or therapeutic ingredients, includes a first portion designed to be fixed to a corresponding bone bed remaining from a previous implant, and a second portion designed to be inserted in a corresponding articular area of the patient, the first portion and the second portion being attached by adjustable connecting means.

A hip prosthesis device including a femoral stem, the femoral stem including an elongate stem sleeve having a blind hole extending in a longitudinal direction and a hole opening at an upper frontal end of the stem sleeve; a stem core having an elongate stem shaft inserted in the blind hole and slidable in the longitudinal direction, a neck having a lower neck portion and an upper neck portion, a lower end of a lower neck portion attached to an upper end of the stem shaft, the upper neck portion attachable to a femoral head; a shock absorber mechanism operatively provided between the stem shaft and the stem sleeve to act against a downwardly directed longitudinal sliding motion of the stem shaft relative to the stem sleeve; and a closure cap positioned to close the hole opening with a through hole which the neck extends with its lower neck portion.

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 CoCr, 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.