Metatarsal-phalangeal replacement joint

An endoprosthetic device for replacement, in a living body, of a first metatarsal phalangeal joint, comprising:

• (a) a biologically compatible-metallic metatarsal component having:
• (i) a distal head and with a smooth distal surface having a superior part-spherical convex phalangeal surface and two inferior, side-by-side concave sesamoidal surfaces, which are separated by an intersesamoidal ridge, blending smoothly with each other;
• (b) a phalangeal component having:
• (i) an axially extending distal stem for intramedullar implantation into a proximal phalanx;
• and
• (ii) a proximal head, integrally formed with said distal stem, having a smooth proximal circular surface at least a major portion of which is a biologically compatible plastics material having a part-spherical concave surface having a similar radius of curvature as said superior part-spherical convex phalangeal surface;
• and
• (c) a sesamoidal component having:
• (i) An elongated flexible planar element including means for securing said element, adjacent a distal end thereof, to said proximal phalanx, and
• (ii) tibial and fibular sesamoidal elements mounted on said planar element in spaced lateral relationship to each other adjacent a proximal end thereof, for articulation with said inferior concave sesamoidal surfaces of said metatarsal component.