Outcomes and complications of conversion THA after internal fixation of proximal femur fractures: a systematic review

The goal of this systematic review is to analyse clinical results and complications of conversion total hip arthroplasty (cTHA) after failure of internal fixation (IFix), distinguishing according to the initial fixation method: intramedullary nail, plate/screw systems, and cannulated screws. PubMed, EMBASE, and Cochrane database were firstly accessed in April 2025, and lastly checked on July 2025, to identify studies addressing patients who underwent to cTHA after sustaining proximal femoral fractures with subsequent IFix. The PRISMA guidelines were followed, and the quality of studies was assessed. Data were extracted from the identified articles and summarised. Twelve retrospective studies on 1,260 patients analyzed complications of conversion to total hip arthroplasty (cTHA) after internal fixation of the femur. After fixation with an intramedullary nail, cTHA showed a 6.01% dislocation rate, 3.14% periprosthetic fractures, 2.59% aseptic loosening, and 3.41% periprosthetic infections, with a 3.82% reoperation rate. Fixation with a plate/screw system resulted in fewer complications but a higher incidence of periprosthetic fractures (11.57%). A notably higher dislocation rate of 10.04% was observed following fixation with cannulated screws. This review confirms that cTHA after IFix of proximal femoral fractures is associated to an elevated rate of perioperative complications, with a higher incidence when cTHA is performed after intramedullary nail fixation; a higher incidence of intraoperative periprosthetic fractures is observed on those patients treated by plate/screws system at first surgery. Unexpectedly, a higher rate of implant dislocations is recorded in those patients undergoing cTHAs after IFix by cannulated screws.