Bone Fixation of Mpact Double Mobility Cup

Inclusion Criteria: * primary hip replacement * patients 18 to 80 years old * patients who accept the follow-up schedule Exclusion Criteria: * femoral neck fracture * patients requiring grafts * progressive local or systemic infections * patients presenting muscular deficiency, neuromuscular disease or vascular insufficiency of the involved limb * patients suffering from diseases that can compromize the recovery to independent mobility * patients with BMI \> 40 * patients with cognitive diseases that can compromize their participation in the study * patients living in geographical area not allowing the clinical follow-up to be performed * patients participating in other biomedical research * patients \<18 years old * patients \> 80 years old * pregnant or breast feeding women