Safety and Effectiveness of the HIT Reverse HRS

This is a randomized, controlled, multi-center clinical trial. Subjects meeting inclusion and exclusion criteria will be recruited from patients undergoing primary THA at up to 20 investigational sites. Subjects in the Experimental Arm will receive the Investigational Device. Subjects in the Control Arm will receive one of the already-marketed semi constrained uncemented hip systems using a metal on highly cross-linked polyethylene (XLPE) or ceramic-on-XLPE bearing combination. The following hip systems will be eligible for subjects in the Control Arm:

• DePuy Synthes CORAIL® or DePuy Synthes ACTIS™ Total Hip System in combination with DePuy Synthes PINNACLE™ Complete Acetabular Hip System;
• Zimmer Biomet Taperloc®, Zimmer Z1™ Cementless Femoral Hip Stem System or Zimmer Biomet AVENIR® Complete Hip System in combination with Zimmer Biomet G7® Acetabular System;
• Stryker Accolade® II femoral stem in combination with Stryker Trident® II acetabular cup;
• Smith & Nephew ANTHOLOGY® Total Hip System in combination with Smith & Nephew R3® Acetabular System.

Surgery, post-surgical care, and rehabilitation will be per standard of care (SOC) for both arms.

Inclusion criteria

• Patient requires primary THA due to NIDJD or any of its composite diagnoses such as osteoarthritis, avascular necrosis, posttraumatic arthritis, slipped capital epiphysis, fracture of the pelvis, and diastrophic variant requiring unilateral primary THA.
• Patient is between 50 (inclusive) and 75 (inclusive) years of age at the time of enrollment.
• Patient has preoperative medical clearance and is free from or treated for medical conditions that would pose excessive operative risk.
• Patient has a signed and dated Informed Consent Form (ICF).
• Patient is willing and able to participate in required follow-up visits at the investigational site and to complete study procedures and questionnaires.

Exclusion criteria

• Patient has received earlier THA, hemi-arthroplasty, or fusion in the contralateral hip in the last 24 months.
• Patient has received earlier THA, hemi-arthroplasty, or fusion in the contralateral hip more than 24 months ago and has a contralateral hip-specific pain rating of ≥2 on a Numeric Rating Scale 0-10.
• Patient needs bilateral hip replacement or has a planned THA on the contralateral hip joint in the next 24 months.
• Patient needs knee arthroplasty or has a planned total knee arthroplasty in the next 24 months.
• Patient has a known allergy to titanium and/or XLPE.
• Patient has known metal sensitivities to cobalt chromium (CoCr).
• Patient has a history of septic arthritis in the index joint.
• Patient has insufficient acetabular or femoral bone stock in which good anchorage of the implants is unlikely or impossible.
• Patient has total or partial absence of the muscular or ligamentous apparatus.
• Patient has known moderate to severe renal insufficiency.
• Patient has vascular insufficiency, muscular atrophy, or neuromuscular disease in either leg (based on the Investigator's judgment).
• Patient has a deformity of the affected limb or significant anatomic variance of the affected hip.
• Patient has an active malignancy or history of invasive malignancy within the last 5 years, except for superficial basal cell carcinoma or squamous cell carcinoma of the skin that has been definitively treated. Patients with carcinoma in situ of the uterine cervix definitively treated more than 1 year prior to enrollment may enter the study.
• Patient has Paget's disease, Charcot-Marie-Tooth disease, or osteomalacia.
• Patient has an inflammatory DJD including any of its composite diagnoses: rheumatoid arthritis, systemic lupus erythematosus, pigmented villonodular synovitis, juvenile rheumatoid arthritis, and other arthritic processes of inflammatory or autoimmune etiology.
• Patient has any condition that would interfere with self-assessment of pain, function, or quality of life (QoL) required for patient-reported outcomes during the study (based on the Investigator's judgment).
• Patient has a Body Mass Index (BMI) of 40 or higher.
• Patient has an active infection (e.g., hepatitis, Acquired Immune Deficiency Syndrome (AIDS), AIDS-related Complex (ARC)) that is systemic or at the site of the intended surgery.
• Patient is currently participating in any investigational study not related to this study's preoperative or postoperative care.
• Patient is currently pregnant or is planning to become pregnant during the study.
• Patient is a competitive or professional athlete.