An acetabular cup includes an articular insert (1) having a substantially semi-spherical articular cavity (1c), and a spherical head (2) engaged in the articular cavity (1c). A retaining device (10a) opposes the axial release (4) of the spherical head (2) from the articular cavity (1c) of the articular insert (1). For example, the retaining device can take the form of a back-tapered segment (10a) of the articular insert (1). The spherical head (2) is factory mounted in the articular insert (1), by temporarily heating the articular insert (1) and performing sterilization after assembly. In this way, the spherical head (2) retention capacity in the articular insert (1) is increased substantially in order to reduce the risk of luxation.
