Safety and Effectiveness Study of OR3O™ Dual Mobility System in THA

Inclusion Criteria: All subjects: * Subject is a suitable candidate for implanting the OR3O™ Dual Mobility System in primary or revision total hip replacement in the Investigator's judgement. * Subject is skeletally mature in the Investigator's judgement. * Subject is 18 - 80 years old (inclusive). * Subject has any of the following conditions: * Advanced degeneration of the hip joint as a result of degenerative, post-traumatic, or rheumatoid arthritis (RA); * Fracture or avascular necrosis of the femoral head; * Failure of previous hip surgery: joint reconstruction, internal fixation, arthrodesis, hemiarthroplasty, surface replacement arthroplasty, or total hip replacement; * All forms of osteoarthritis (OA); * Patients with hips at risk of dislocation; * Femoral neck fracture or proximal hip joint fracture. * Subject provides written informed consent for study participation using an Independent Ethical Committee (IEC) / Institutional Review Board (IRB) approved consent form before any study procedures are performed, including pre-operative data review and/or collection of data on electronic Case Report Forms (eCRFs). * Subject is willing and able to participate in required follow-up visits and is able to complete study activities. * Subject has all required study pre-operative and operative data available in their medical record for collection if consent is given after their THA surgery. Revision Subjects: * Subject has a REDAPT™ Modular Shell implanted whi…