OPS™ With Direct Anterior Approach (DAA)

Inclusion Criteria: * Patients who understand the conditions of the study and are willing to return to the clinical site at 2 weeks postoperatively. * Patients of either gender who are between 21-85 years (inclusive) at the time of consent. * Patients with a diagnosis of osteoarthritis (including post-traumatic osteoarthritis), rheumatoid arthritis or avascular necrosis and are considered by the Investigator to be clinically and medically suitable to undergo a primary total hip replacement. * Patients who meet the indications and none of the contraindications listed in the Instructions for Use (IFU) supplied by the manufacturer for the femoral stem and acetabular cup to be implanted. * Patients who meet the indications and none of the contraindications listed in the Instructions for Use (IFU) supplied by the manufacturer for OPS™ Femoral Plan and OPS™ Femoral Patient Specific Instruments. Exclusion Criteria: * Patients who are unable to provide informed consent. * Patients who are unable to comply with all the required study procedures. * Patients who are currently involved in any personal injury litigation, medical-legal or worker's compensations claims.