Abstract: A hip prosthesis comprises a one piece element including a head, a plate portion, a neck interconnecting the head and plate portion, and a flexible femoral rod which includes thin longitudinal elements extending away from the head in opposition to one another. The longitudinal elements are obtained by providing at least a longitudinal cutting in the rod which extends to its end opposite the head. A slot in each end coincident with the cutting houses a linking part for holding the elements together in one plane while permitting their relative movements in a second substantially orthogonal plane. The elements are made in one piece with the head, the neck and the plate of the prosthesis, with the rod itself being forged from a single piece.