Hip or shoulder prosthesis and placement instruments

A prosthesis configured to replace at least a head of a femur or a head of a humerus, said prosthesis comprising:

• a head component (1), said head component comprising:
• a front face (11) and a rear face (12);
• a bore (13) formed in said rear face;
• and a first recess (14A) and a second recess (14B) formed in said rear face, wherein said first and second recesses are configured to be releasably engaged by protrusions of an insertion device usable for placement of said head component into an acetabulum of the patient's pelvis or a glenoid of the patient's shoulder blade;
• a metaphyseal component (2), said metaphyseal component formed as a substantially straight component having a first end and a second end, and comprising:
• a body portion (26) with a transverse aperture (21);
• a shank portion (22) at said first end configured for threaded engagement within said bore (13) of said head component (1);
• and a longitudinal hole (23) configured to begin at a second end, and to transect and extend beyond said transverse aperture (21);
• a diaphyseal nail (3), said diaphyseal nail comprising:
• a first portion (31) and a second portion (33);
• wherein said first portion is configured to be received in a portion of the femoral or humeral canal and comprises:
• one or more apertures (32) configured to receive one or more corresponding screws for fastening said diaphyseal nail to the femur or the humerus;
• wherein said second portion is configured to be received within said transverse aperture (21) of said metaphyseal component (2), and comprises a transverse hole (36);
• and
• a locking device (24), said locking device configured to be received in said longitudinal hole of said metaphyseal component, and to at least be received within a portion of said transverse hole (36) of said diaphyseal nail;
• at least a portion of longitudinal hole comprising internal threading configured to threadably engage an externally threaded portion of said locking device.