There are two distinct aims of this study:

1. This prospective study is designed to document the long-term (10-year) radiographic and clinical outcomes of a new type of highly cross-linked polyethylene liner which contains vitamin E as an anti-oxidant, (E-Poly), in a group of primary total hip arthroplasty subjects. The clinical outcome of E-Poly will be compared to a group of subjects receiving Arcom XL polyethylene.
2. This study is also designed to document the long-term (10-year) radiographic and clinical outcomes of a new cementless acetabular component having a titanium porous surface (Regenerex). The clinical outcome of this new FDA cleared device will be compared a group of subjects receiving an acetabular component having a plasma sprayed surface.

Inclusion Criteria:

• Subjects requiring primary total hip replacement
• Subjects with diagnosis of osteoarthritis or traumatic arthritis
• Subjects who demonstrate the ability to return for follow-up for the next 10 years

Exclusion Criteria:

• Subjects with limited life span
• Subjects with difficulty in comprehending study protocol for any reason.
• Subjects with inflammatory disease, previous infection or those requiring revision hip surgery.
• Subjects with avascular necrosis
• Subjects whose bony structures are so small that a femoral head less than 32mm in diameter must be used.
• Subjects whose bony structure deviates substantially from the general norm sufficiently to require non-standard techniques and non-standard implants. Specific examples of these are total dislocation of the hip, severe coxa vera deformity, severe forms of multiple epiphyseal dysplasia
• Subjects with complex disease entities which significantly increase the risks of the surgery such as any major platelet abnormality, hematological disorder, positive for HIV or any other major medical complication which substantially reduces longevity.
• Female subjects that are pregnant or who may suspect they are pregnant or who plan to become pregnant while participating in this study.