Articular prosthetic acetabulum, in particular for the hip or shoulder joint, comprising: - a dome (2) of rigid and biocompatible material, which has a roughly hemispherical general shape, with revolution symmetry around an axis (X- X ') - called central - and which has a convex outer face (20) adapted to be inserted and fixed in the cotyloid cavity of the bone； - a helmet (3) of implantable material, in particular of metal, ceramic or biocompatible composite material, suitable for being housed inside said dome (2), this helmet (3) having a substantially hemispherical internal cavity (33) , destined to receive the head of an articular prosthesis, and which has a mouthpiece whose external wall (31) has a truncated conical shape, of low taper, which widens outwards； - a ring (4) capable of being detachably fixed in the mouth of said dome (2) and having an internal wall (41) also conical, whose shape is complementary to that of the external wall (31) of the mouth of the helmet (3), so that it is possible there to embed said helmet (3) by ensuring an assembly of the morse cone type between the ring (4) and the helmet (3)； said dome (2) having an internal cavity (5) surrounded by a mouth (6), while said ring (4) has an outer wall portion (40) whose surface has a complementary shape to that of the surface of said mouth (6), so that it can be inserted axially inside said mouth (6) and be removable with respect to said dome (2)； characterized in that said ring (4) and said dome (2) are secured by means of screwing, said ring (4) having an external annular base (7), apt to rest against the edge (21) of the dome (2) ) when the ring (4) is fixed to the latter, this external annular base (7) being perforated with several holes (70) for the passage of fixing screws (9) intended to be screwed into threaded holes (8), of longitudinal axis parallel to said central axis X-X ', arranged in the wall of the dome (2), these fixing screws (9) and these threaded holes (8) constituting sai
