To demonstrate the safety and effectiveness of the Trinity™ BIOLOX delta™ Ceramic-on-Ceramic Total Hip System in comparison to the Trinity™ Acetabular Hip System,which is FDA cleared for use in the U.S. The comparison will be based upon clinical success at the Month 24 endpoint.

The clinical research results for the Trinity™ BIOLOX delta™ Ceramic-on-Ceramic Total Hip System will be compared to the control device

Clinical success is based upon Harris Hip Scores to evaluate functional status, adverse events, radiological assessments and no device failure (defined as removal, replacement, or modification of any device component).

Inclusion Criteria:

1. preoperative Harris Hip Score of ≤ 70.
2. preoperative Harris Hip Total Pain score of at least moderate.
3. diagnosed with non-inflammatory degenerative joint disease including osteoarthritis and avascular necrosis, rheumatoid arthritis, correction of functional deformity, developmental hip dysplasia (DDH) and congenital hip dysplasia (CDH).
4. pain rating of none or slight and are at least 12 months post-operative in the contralateral hip, if applicable.
5. have sufficient femoral and acetabular bone stock as determined by a clinician, and are suitable to receive implants as confirmed by x-rays.

Exclusion Criteria:

1. have a nutritional problem (protein, calorie, or vitamin/mineral deficiency) that may impair wound healing mechanisms as determined by the clinician /investigator.
2. have a neurological disorders which may interfere or adversely affect gait, balance, or weight bearing (e.g. muscular dystrophy, multiple sclerosis).
3. diagnosed with metabolic disorders (e.g. osteomalacia), which may impair bone metabolism.
4. diagnosed systemic disease that would affect their welfare or the overall outcome of study (i.e. Paget's disease, renal osteodystrophy)
5. immunologically suppressed.
6. receiving systemic steroid therapy, excluding inhalers, within 3 months prior to surgery.
7. diagnosed Charcot's disease, metastatic or neoplastic disease.
8. evidence of active infections that may spread to other areas of the body (e.g. osteomyelitis, pyogenic infection of the hip joint, overt infection, untreated urinary tract infection, etc.).
9. presence of a previous prosthetic hip replacement device (any type, including surface replacement arthroplasty, endoprosthesis, etc.) in the hip joint to be operated.
10. previous Girdlestone procedure (resection arthroplasty) or surgical fusion of the hip to be operated.
11. diagnosed with systemic lupus erythematosus, pigmented villonodular synovitis, juvenile rheumatoid arthritis or other diagnoses with autoimmune etiology.
12. diagnosed with osteoporosis or as evidenced on a DEXA scan for males over 75 or females over 65 years of age (within the last 12 months).
13. require structural bone grafts in order to support the prosthetic component(s) or to shape the bone to receive the implant(s).
14. have acute femoral neck fracture or hip fractures.
15. have an above the knee amputation of the contralateral and/or ipsilateral leg.
16. have an existing total hip arthroplasty in the contralateral hip with a pain rating of 3 or more on a scale of 0 to 10, where 0 is "no pain" and 10 is "severe pain".
17. have had a total hip arthroplasty in the contralateral hip within the past 12 months.
18. have previously received a metal-on-metal hip arthroplasty.
19. have a highly communicable disease or diseases that may limit follow-up (e.g. immunocompromised conditions, hepatitis, active tuberculosis, etc.).
20. have any known sensitivity to device material.
21. Females who are pregnant.
22. Patients who are prisoners.