Inclusion Criteria:  Patients of both genders; Patients of all ages, but > 18 years old; Patients with primary and secondary coxarthrosis; Patients with rheumatoid arthritis; Patients with avascular necrosis; Patients with neck (not diaphyseal) fractures; Patients requiring a primary hip arthroplasty.  Exclusion Criteria:  Patients requiring a revision of a previous stem; Patients with proven active or suspicious infections; Patients with known hypersensitivity to used materials; Patients with known active neoplastic or metastatic diseases; Patients with significant neurological or musculoskeletal disorders that may affect functional recover; Patients with proven haemophilic disease; Patients with unwilling or unable to comply with rehabilitation or inability to return for follow-up visits; Women with pregnancy or childbearing capacity or breast-feeding; Subjects already enrolled in other clinical trials.