A prosthetic head with a body having the shape of a cup shaped as a hemispherical cap provided with an external surface, an internal surface and a lower edge shaped as a circumference, fixing means to fix the prosthetic head to the cotyle, and a projection abutting from the internal surface of the prosthetic head in such manner to define an annular step, and a truncated-conical portion obtained in the internal surface of the body of the prosthetic head starting from the lower edge of the prosthetic head, the truncated-conical portion of the prosthetic head being suitable for being coupled in conical coupling mode with a truncated conical part of an insert intended to be inserted in the prosthetic head. he projection is shaped as a portion of a spherical cap.
