Dual Mobility Articulation in Conversion of Failed Proximal Femoral Fixation into Total Hip Arthroplasty

Background: Failure of fixation of proximal femoral fractures (PFFs) that is mostly successfully treated with reduction and internal fixation may occur in cases with unstable fracture patterns, poor bone quality, or severe osteoporosis. Salvage options comprise either a revision of internal fixation or conversion arthroplasty.
Objective: This study describes the clinical and radiological outcomes achieved with dual mobility (DM) cups in the conversion of failed proximal femoral fracture fixation (PFFF) to total hip arthroplasty (THA).
Patients and Methods: From January 2020 to January 2024, a prospective study was conducted including 30 patients after failure of PFFF managed by conversion hip arthroplasty with DM cups. Posterior approach and DM cups were selected for all patients, either cemented or cementless, depending on bone quality. Indications for conversion procedure were PFF with mechanical failure, avascular necrosis, fracture nonunion, and secondary hip osteoarthritis. Radiological evaluation was performed to assess the position of acetabular and femoral components, cement mantle, and loosening, and functional assessment using the Harris Hip Score.
Results: This case series included 16 males and 14 females (12 right, 18 left). The mean age at the revision time was 63.2 ± 6.2 years. According to the original fracture, there were 9 patients with femoral neck fracture (FNF) (30%), 20 patients with intertrochanteric fracture (66.7%), and only one case with trochanteric fracture with subtrochanteric extension (3.3%). The indication for conversion THR was nonunion of the old fracture for 24 hips (80%), avascular necrosis for 5 hips (16.7%), and osteoarthritis secondary for fixation for only one hip (3.3%). Seventeen patients received cemented DM cups (56.7%), while 13 patients received cementless DM cups (43.3%). Standard cemented stem was used in 10 cases (33.3%), standard cementless stem in 13 cases (43.3%), and long stem (6 cemented and one cementless) in 7 cases (23.3%).
Conclusion: Patients with failed PFFF who used dual mobility cups experienced a lower incidence of dislocation and an improvement in their Harris Hip Score.