The implant has a humeral head in rolling and/or friction contact with concave-shaped head surface (S). The head surface defines an outer periphery (P) provided with a rim (R) that protrudes toward top with respect to the head surface. The rim is discontinuous so as to form rim segments i.e. side segment (R1) and upper segments (R2), separated by slots (F). The rim projects outside with respect to the outer periphery of the head surface and extends on a portion of the periphery of the surface. The surface defines upper area and lower area when the implant is positioned on scapula.
