Dual Mobility Cup Fixation Augmented by Pegs and Screws for Total Hip Arthroplasty in a Geriatric Population with Osteoporosis: Short- and Medium-Term Results of a Retrospective Series of 45 Patients

Abstract

Introduction: Total Hip Arthroplasty (THA) requires stable primary fixation of the acetabular implant. The main objective of this study was to evaluate, in a geriatric population, the radiological results and the medium-term survival of a Dual Mobility Cup (DMC) with hydroxyapatite coating and tripod fixation augmented by 2 pegs and a screw. Hypothesis: In a geriatric population prone to osteoporosis, this type of implant offers medium-term survival >95% and a complication rate similar to the data from the literature. Methods: This single-center retrospective study included 45 patients (30 women and 15 men) with a mean age of 79.3±5.4 years. Patients included were over 70 years old, with this type of implant for any indication for a first-line THA (30 cases) or revision (15 cases), the initial indication was a proximal femoral fracture in 71% of cases. For each patient, X-rays, clinical scores (Oxford Hip Score, EQ-5D-5L, Parker score) and implant survival were evaluated at the last follow-up. Results: The mean radiological follow-up was 25.4±16 months. Clinical follow-up was 39.9±14 months for 30 patients. For 15 patients (4 lost to follow-up and 11 deceased), clinical data were not available. For 3 patients, periprosthetic osteolysis was observed in zones I and II, as per the DeLee and Charnley system. The Oxford Hip Score was 41.1±8.8 (range: 16-48). The mean VAS was 0.9±1.6 and the mean EQ-5D-5L was 0.6±0.3. Discussion: The use of DMC with fixation augmented by pegs and screws is safe and effective in the short and medium term for THA in a geriatric population.