Two-year radiologic assessment of the Pinnacle cup—a migration analysis with EBRA

Abstract

Abstract Introduction The most common cause of failure in total hip arthroplasty (THA) is aseptic loosening. Uncemented cup migration analysis by EBRA (Einzel-Bild-Roentgen-Analyse) has shown to be a good predictive indicator for early implant failure if the cup migrates more than 1 milimeter (mm) within the first 2 years after surgery. In this study, we investigated the migration behaviour of an uncemented press-fit cup after 2 years follow-up. Materials and methods Applying a retrospective study design, we reviewed all consecutive patients who received an uncemented press-fit cup at our Department between 2013 and 2018. A total of 484 patients were identified. We reviewed medical histories and performed radiological measurements using EBRA-Cup software. EBRA measurements and statistical investigations were performed by two independent investigators. Results A total of 165 cups in 159 patients (female: 90; male: 69) met our inclusion criteria. Mean age at surgery was 66.7 (range 18.4–90.5) years. EBRA migration analysis showed a mean total migration of 0.7 mm (range 0.0–6.3) over our follow-up period of 2 years. Of the investigated cups, 53.2% showed less than 1 mm migration in the investigated follow-up period. Conclusion In conclusion, the Pinnacle cup used in our study provides low mean migration at final follow-up. Based on the assumption of secondary stabilization, good long-term outcome of the Pinnacle cup can be expected. Trial registration number and date of registration Number: 20181024-1875; Date: 2018-09-20