A trial medical instrument for aligning an acetabular component, comprising: a first portion configured to fit within a patient's acetabulum; and a second portion extending from the first portion; wherein the second portion extends from the first portion in a direction that mimics a shape formed by a femoral implant component coupled with an acetabular implant component when a femur to which the femoral implant component is coupled is in a position relative to an acetabulum to which the acetabular implant component is coupled that is near an extent of a typical range of motion of the femur. As used herein, the phrase extent of a typical range of motion describes typical angular displacements of a femur as usually limited by patient anatomy.

In one embodiment a method of implanting a prosthetic includes implanting a first member including a concave articulation surface portion defined by a first radius of curvature in a first bone, implanting in a second bone a second member including a first convex articulation surface portion defined by a second radius of curvature and a second convex articulation surface defined by a third radius of curvature, wherein the second convex articulation surface is defined by the lemon portion of a spindle torus and each of the second radius of curvature and the third radius of curvature has a length that is different from the length of the first radius of curvature by less than 0.05 millimeters and wherein the origin of the second radius of curvature is not coincident with the origin of the third radius of curvature, and bringing the first member into slidable contact with the second member.

A method for implantation of a locking member in a hip joint of a patient is disclosed. The method comprises; performing an operation in a hip joint surgically or arthroscopically, placing an artificial hollow caput femur surface mounted onto caput femur, placing a locking member for assisting in the fixation of the artificial caput femur surface with at least one extending portion adapted to clasp a portion of the caput and/or collum femur. The locking member comprises an element locking the artificial caput femur surface such that the caput femur remains clasped and restrained in said artificial caput femur surface.

Femoral heads, mobile inserts, acetabular components, and modular junctions for orthopedic implants, e.g., hip replacement implants, and methods of using femoral heads, mobile inserts, acetabular components, and modular junctions for orthopedic implants are provided. Prosthetic femoral heads, mobile inserts, and acetabular components are provided that can alleviate soft tissue impingement, reduce implant wear, and/or reduce frictional torque. Modular junctions are provided that can minimize the incidence of loosening and micromotion that can occur at modular junctions of orthopedic implants.

Embodiments of a system and method for assessing hip arthroplasty component movement are generally described herein. A method may include receiving data from a sensor embedded in a femoral head component, the femoral head component configured to fit in an acetabular component, determining information about a magnetic field from the data, and outputting an indication of an orientation, coverage, or a force of the femoral head component relative to the acetabular component.

Embodiments of a system and method for assessing hip arthroplasty component movement are generally described herein. A method may include receiving data from a sensor embedded in a femoral head component, the femoral head component configured to fit in an acetabular component, determining information about a magnetic field from the data, and outputting an indication of an orientation, coverage, or a force of the femoral head component relative to the acetabular component.

A locking member for implantation in a hip joint of a patient is provided. The hip joint has a caput femur integrated with a collum femur having a center axis extending longitudinal along the collum and caput femur in the center thereof. The locking member is adapted to assist in the fixation of a medical device, having an artificial hollow caput femur surface, to the collum and/or caput femur, wherein said artificial caput femur surface comprises at least one extending portion adapted to clasp a portion of the caput and/or collum femur, and wherein said locking member comprises an element adapted to lock said artificial caput femur surface such that the caput femur remains clasped and restrained in said artificial caput femur surface.

A locking member for implantation in a hip joint of a patient is disclosed. The locking member is adapted to assist in the fixation of a medical device, having an artificial hollow caput femur surface, to the collum and/or caput femur, wherein the artificial caput femur surface comprises at least one extending portion adapted to clasp a portion of the caput and/or collum femur. The locking member comprises an element adapted to lock the artificial caput femur surface such that the caput femur remains clasped and restrained in the artificial caput femur surface.

In one embodiment a method of implanting a prosthetic includes implanting a first member including a concave articulation surface portion defined by a first radius of curvature in a first bone, implanting in a second bone a second member including a first convex articulation surface portion defined by a second radius of curvature and a second convex articulation surface defined by a third radius of curvature, wherein the second convex articulation surface is defined by the lemon portion of a spindle torus and each of the second radius of curvature and the third radius of curvature has a length that is different from the length of the first radius of curvature by less than 0.05 millimeters and wherein the origin of the second radius of curvature is not coincident with the origin of the third radius of curvature, and bringing the first member into slidable contact with the second member

A prosthetic ball for use in a ball and cup joint system includes a spherical cap articulation portion defined by a first radius of curvature, and a toroidal articulation portion defined by a second radius of curvature having a circular origin such that the toroidal articulation portion is defined by a portion of the inner surface of a spindle torus.