Mechanical assembly of pegs to prosthesis

A method of making a joint prosthesis from a solid metal base, a porous metal peg and a solid metal plug, wherein:

• the solid metal base includes a first solid metal surface and a second solid metal surface spaced from the first solid metal surface, a hole in the first solid metal surface, a hole in the second solid metal surface and an internal wall extending between and defining the holes, the internal wall having a tapered portion and a cylindrical portion, the tapered portion having a minimum internal diameter at the second solid metal surface and a maximum outer diameter at a position between the first solid metal surface and the second solid metal surface, the cylindrical portion of the internal wall extending from the tapered portion to the first solid metal surface, the tapered portion of the internal wall defining a chamfered chamber and the cylindrical portion defining a cylindrical chamber;
• the peg includes a head and a shaft, the head having a first free end, an end surface at the first free end and a tapered wall extending from the first free end to the junction of the head and the shaft, the peg having a maximum outer diameter at the first free end and a smaller outer diameter at the junction of the head and the shaft;
• the plug includes a first solid metal surface, a second solid metal surface spaced from the first solid metal surface and a side wall extending from the first solid metal surface toward the second solid metal surface;
• the method comprising:
• positioning the peg with the tapered wall of the head bearing against the tapered portion of the internal wall and with the shaft of the peg extending outwardly past the second solid metal surface of the solid metal base, wherein the end surface of the head of the peg does not extend beyond the junction of the chamfered chamber and cylindrical chamber in the solid metal base;
• press-fitting the plug into the cylindrical chamber in the solid metal base with the second solid metal surface of the plug bearing against the end surface of the head of the peg and with the side wall of the plug engaging the cylindrical portion of the internal wall defining the cylindrical chamber;
• fixing the solid metal plug to the first solid metal surface of the solid metal base;
• and
• removing any undesirable portion of the solid metal plug extending beyond the first solid metal surface of the base.

An orthopaedic prosthesis comprising:

• a first component comprising a solid portion and a porous portion,
• the solid portion including a first solid surface and a second solid surface spaced from the first solid surface,
• the solid portion having an internal wall extending from the second solid surface toward the first solid surface and having an end at a level between the first solid surface and the second solid surface, the internal wall defining a chamber;
• the second solid surface having an opening at the junction of the internal wall and the second solid surface;
• the porous portion including a peg having a head and a shaft,
• at least a substantial part of the head of the peg being received within the chamber in the solid portion between the first solid surface and the second solid surface,
• a portion of the peg extending outward through the opening in the second solid surface;
• wherein the solid portion extends from the first solid surface to the head of the peg and covers the head of the peg;
• and
• wherein the peg and the second solid surface of the solid portion are not bonded together.

A method of making a joint prosthesis from a solid base, a porous peg and a solid plug, wherein:

• the solid base includes a first solid surface and a second solid surface spaced from the first solid surface, a hole in the first solid surface, a hole in the second solid surface and an internal wall extending between and the holes and defining a chamber;
• the peg includes a head and a shaft, the head having a first free end, the peg having a maximum outer diameter at the first free end and a smaller outer diameter at the junction of the head and the shaft;
• the plug includes a first solid surface, a second solid surface spaced from the first solid surface and a side wall extending from the first solid surface toward the second solid surface;
• the method comprising:
• positioning the peg in the chamber in the solid base;
• press-fitting the plug into the chamber in the solid base with the second solid surface of the plug bearing against the end surface of the head of the peg;
• fixing the solid plug to the first solid surface of the solid base;
• and
• removing any undesirable portion of the solid plug extending beyond the first solid surface of the base.