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 inprimary 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 hipreplacement;

• 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 anIndependent Ethical Committee (IEC) / Institutional Review Board (IRB) approvedconsent form before any study procedures are performed, including pre-operative datareview 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 ableto complete study activities.

• Subject has all required study pre-operative and operative data available in theirmedical record for collection if consent is given after their THA surgery.

Revision Subjects:

• Subject has a REDAPT™ Modular Shell implanted which does not require revision orwill receive a REDAPT™ Modular Shell during revision THA.

• Subject has a S+N compatible stem which does not require revision or will receive aS+N compatible stem during revision THA.

Exclusion Criteria:

All subjects:

• Subject has conditions that would eliminate or tend to eliminate adequate implantsupport or prevent the use of an appropriately-sized implant, e.g.:

• blood supply limitations;

• insufficient quantity or quality of bone support, e.g., osteoporosis, metabolicdisorders which may impair bone formation, radioactive bone disease, tumoraround hip joint, and osteomalacia;

• infections or other conditions which may lead to increased bone resorption.

• Subject has dysplasia of hip joint with CROWE Grade III, IV.

• Subject has bodily disease(s) that may interfere with THA survival or outcome.

• Subject has life expectancy of less than 10 years.

• Subject has mental or neurological conditions which impair the subject's ability orwillingness to restrict activities that may put the affected limb at risk.

• Subject has physical conditions or activities which tend to place extreme loads onimplants, e.g., Charcot joints, muscle deficiencies, multiple joint disabilities.

• Subject has neuromuscular dysfunctions (paralysis, myolysis and abductor muscleweakness) which will cause unstable hip joint or abnormal gait after surgery.

• Subject has an emotional or neurological condition that would pre-empt their abilityor willingness to participate in the study.

• Subject has an active infection - systemic or at the site of intended surgery.

• Subject has a Body Mass Index > 40.0 kg/m².

• Subject has a known allergy to any component of the devices used in the study.

• Subject is pregnant or breast feeding.

• Subject is entered in another investigational drug, biologic, or device study within 30 days of active study participation.

Revision Subjects:

• Subject has inadequate implant support with an increased risk of implant failure ifsupport is not achieved, poor bone quality exists, or smaller sized implants areutilized.

• Subject needs revision of a fractured ceramic head or liner.

• Subject was already enrolled into this study as primary THA case.