Retrospective Observational Cohort Study of SYMBOL CUP DM 1

Description according to PICOS framework: Patients: \- Adult men and women requiring a primary total hip arthroplasty Intervention: \- Primary THA with SYMBOL CUP DM HA hemispherical dual mobility acetabular implant. Comparator: None Outcomes: * Safety 1: Implant survival over 2-year follow-up. * Safety 2: All adverse events, with focus on implant dislocation, infections, revision surgery * Efficacy 1: Harris Hip Score (HHS) at baseline and 1-year follow-up. * Efficacy 2: Modified HHS consisting of pain + functional subscores at baseline, 1-year and 2-year follow-ups. * Efficacy 2: Devane score at baseline, 1-year and 2-year follow-ups. * Efficacy 3: Charnley classification at baseline, 1-year and 2-year follow-ups. Study design: * single-center retrospective observational cohort study of consecutively operated patients who underwent primary total hip arthroplasty 2 years prior to study start. * Prospective 2-year follow-up letter and phone questionnaire.