Abstract: An orthopaedic joint prosthesis assembly includes a head part of an orthopaedic joint prosthesis component and an alignment guide. The head part has a spherical bearing. surface for articulation with a corresponding joint surface, and an assembly surface having a first bore formed in it for receiving a spigot on another part of the orthopaedic joint prosthesis, The bore has a first axis that extends perpendicular to the assembly surface. There is a discontinuity at an interface between the bearing surface and the assembly surface, and the assembly surface is arranged on a plane which is parallel to, or contains, a plane which is defined by the opening to the bore in the head part when the head part is viewed from one side in cross-section. The alignment guide has an axial portion and an arm extending from the axial portion.

Abstract: An orthopaedic joint prosthesis assembly includes a head part of an orthopaedic joint prosthesis component and an alignment guide. The head part has a spherical hearing surface for articulation with a corresponding joint surface, and an assembly surface having a first bore formed in it for receiving a spigot on another part of the orthopaedic joint prosthesis. The bore has a first axis that extends perpendicular to the assembly surface. The alignment guide has an axial portion defining a second axis and an arm extending from the axial portion. The arm includes a distal portion which is configured to engage the assembly surface, with the axial portion being arranged to engage the bearing surface of the head part when the head part is mounted within the guide such that an impaction force applied along the second axis is directed along the first axis.

Abstract: An orthopaedic joint prosthesis assembly includes a head part of an orthopaedic joint prosthesis component and an alignment guide. The head part has a spherical bearing surface for articulation with a corresponding joint surface, and an assembly surface having a first bore formed in it for receiving a spigot on another part of the orthopaedic joint prosthesis. The bore has a first axis that extends perpendicular to the assembly surface. There is a discontinuity at an interface between the bearing surface and the assembly surface, and the assembly surface is arranged on a plane which is parallel to, or contains, a plane which is defined by the opening to the bore in the head part when the head part is viewed from one side in cross-section. The alignment guide has an axial portion and an arm extending from the axial portion.