A modular prosthetic component (10, 70) configured for implantation within a bone, the modular prosthetic component (10, 70) comprising: a stem having an elongate shaft portion defining a longitudinal axis, wherein the stem includes a nose for insertion within an intramedullary canal of the bone; a head (14, 106) extending from said stem, said head (14, 106) having a flange; and a sleeve (16, 71, 80, 90, 100, 120,130) dimensioned for receipt on said head (14, 106), characterised in that the head includes an exterior tapered surface at a first end of the head for receipt of a second modular component, and an exterior tapered surface at a second end of the head for receipt of the sleeve, said first and second ends sharing a common central longitudinal axis and being separated by the flange, said sleeve (16, 71, 80, 90, 100, 120, 130) formed at least partially from a highly porous biomaterial, said highly porous biomaterial allowing tissue ingrowth therein, said sleeve (16, 71, 80, 90, 100, 120, 130) having an exterior surface (64, 72, 82, 92, 102), an interior surface defining an internal bore into which the second end of the head (14, 106) is received, and first and second opposing ends (66, 67) connecting said exterior surface (64, 72, 82, 92, 102) and said interior surface, said sleeve (16, 71, 80, 90, 100, 120, 130) dimensioned for sliding receipt on the exterior tapered surface of said head (14, 106) in a first longitudinal direction, wherein said flange limits movement of said sleeve (16, 71, 80, 90, 100, 120, 130) in the first longitudinal direction, wherein said flange is sized to limit movement of said sleeve (16, 71, 80, 90, 100, 120, 130) in said first longitudinal direction so that the sleeve (16, 71, 80, 90, 100, 120, 130) is captured by said flange and the bone when said stem is implanted in the bone. a stem having an elongate shaft portion defining a longitudinal axis, wherein the stem includes a nose for insertion within an intramedullary canal of the bone; a head (14, 106) extending from said stem, said head (14, 106) having a flange; and a sleeve (16, 71, 80, 90, 100, 120,130) dimensioned for receipt on said head (14, 106), characterised in that the head includes an exterior tapered surface at a first end of the head for receipt of a second modular component, and an exterior tapered surface at a second end of the head for receipt of the sleeve, said first and second ends sharing a common central longitudinal axis and being separated by the flange, said sleeve (16, 71, 80, 90, 100, 120, 130) formed at least partially from a highly porous biomaterial, said highly porous biomaterial allowing tissue ingrowth therein, said sleeve (16, 71, 80, 90, 100, 120, 130) having an exterior surface (64, 72, 82, 92, 102), an interior surface defining an internal bore into which the second end of the head (14, 106) is received, and first and second opposing ends (66, 67) connecting said exterior surface (64, 72, 82, 92, 102) and said interior surface, said sleeve (16, 71, 80, 90, 100, 120, 130) dimensioned for sliding receipt on the exterior tapered surface of said head (14, 106) in a first longitudinal direction, wherein said flange limits movement of said sleeve (16, 71, 80, 90, 100, 120, 130) in the first longitudinal direction, wherein said flange is sized to limit movement of said sleeve (16, 71, 80, 90, 100, 120, 130) in said first longitudinal direction so that the sleeve (16, 71, 80, 90, 100, 120, 130) is captured by said flange and the bone when said stem is implanted in the bone.