Dual mobility cups in total hip arthroplasty after failed internal fixation of proximal femoral fractures

Introduction: Performing total hip arthroplasty (THA) following failed internal fixation of proximal femur fractures is associated with an elevated risk of implant dislocation. We hypothesized that using a dual mobility (DM) cup will help to reduce the risk of postoperative instability in this specific context. Material and methods: This was a retrospective study of 33 consecutive patients who underwent DM THA following failed internal fixation of a proximal femur fracture. The clinical assessment consisted of the Postel-Merle d'Aubigne and HHS scores along with an analysis of preoperative and follow-up radiographs. The primary outcome was the occurrence of implant dislocation. Results: At the last follow-up (44 +/- 24 months), 7 patients had died and 0 were lost to follow-up. Only one dislocation had occurred (3%). The mean PMA and HSS scores of 14.8 and 80 respectively were significantly better than the preoperative scores. There were no cases of aseptic loosening. Conclusion: The use of DM cups in the context of THA following failed internal fixation of proximal femur fractures helps to reduce the risk of dislocation. Thus DM cups are recommended in this indication with high risk of postoperative instability. (C) 2019 Elsevier Masson SAS. All rights reserved.