The proposed study is a prospective evaluation of data from patients undergoing primary total hip arthroplasty using the Trident II acetabular cup. Fifty patients will be recruited for this study. All patients that qualify for the study per the inclusion-exclusion criteria and provide written informed consent will receive the Trident II acetabular cup and RSA beads. Implant stability, through RSA, will be measured throughout the first two postoperative (post-op) years per the following schedule: immediate post-op and 6 weeks, 3 months, 6 months, 1 year, and 2 years following surgery. Patients will be discharged and seen for follow-up assessments as per standard of care. Adverse events that are related to the index joint will be collected. Health outcome questionnaires will be collected. The health outcome questionnaires will include: EQ-5D, HOOS JR and Harris Hip Score. Health outcome questionnaires will be completed pre-operatively and again at 6 weeks, 3 months, 6 months, 1 year and 2 years following surgery. Conventional x-ray analysis will be performed pre-operatively and again at 6 weeks, 1 year and 2 years following surgery.