In a prospective register-based study, we aim to evaluate the implant survival, clinical outcomes and X-ray findings by following a cohort of patients operated with the Trident II cup.

Data will be collected from a cohort consisting of minimum 500 total hip arthroplasties. The patients will be recruited from multiple high volume centers in Sweden. To determine if there is evidence of inferiority as per benchmarking recommendations by The Orthopaedic Data Evaluation Panel the following parameters will be studied: Clinical parameters such as EQ-5D, Oxford Hip Score and Forgotten Joint Score, preoperative and after 1, 3, 6 and 10 years. Conventional radiography will be done preoperatively, postoperatively, 3, 6 and 10 years after total hip replacement. CTMA will be done postoperatively, 3 and 6 month and 2 years after total hip replacement.

Inclusion Criteria:

• Primary hip replacement
• Eligible for uncemented fixation of the acetabular component
• Suitable for one of the stem designs from Stryker Orthopaedics
• Accepts follow-up according to the study protocol

Exclusion Criteria:

• Difficulties to understand written information due to language problems or other reasons
• Use of augments needed
• Acute hip fracture
• Tumor in the hip joint

Due to regulations associated with national registers in Sweden alla data will be presented on an aggregated level, individual patient data will not be shared.