Two-Stage Reconstruction for Failed Subtrochanteric Femur Fixation with Peri-Implant Infection and Severe Proximal Femoral Bone Loss: A Case Report.

Introduction: Subtrochanteric femur fractures are difficult to manage due to high mechanical stresses and complex deforming forces. Treatment often involves placing an intramedullary nail (IM nail) for stabilization and early mobilization. Despite being the preferred fixation method, IM nail constructs remain vulnerable to failure, and repeated fixation attempts can compromise remaining bone stock. When fixation failure occurs in conjunction with early post-operative infection, the combined instability and bone loss may necessitate staged reconstruction. Case Report: A 40-year-old female sustained a right subtrochanteric femur fracture after a motor vehicle collision and underwent IM nail fixation utilizing a recon-style design. Within 1 month, she developed progressive displacement with proximal screw cutout and underwent hardware removal and revision nailing utilizing a cephalomedullary design with a lag screw. Nineteen days later, the revision construct failed with a new femoral neck fracture and further proximal femoral erosion. She subsequently developed thigh pain and erythema, with elevated inflammatory markers and aspiration cultures positive for Staphylococcus capitis, confirming early post-operative peri-implant infection. The decision was made to proceed with a two-stage reconstruction. Stage 1 involved explantation of all hardware, aggressive synovectomy, and placement of a high-dose static antibiotic spacer consisting of a cemented acetabular ball and an antibiotic cement-coated IM nail. After clinical resolution of infection, she underwent second stage revision total hip arthroplasty through a posterior approach. Reconstruction utilized a 54-mm press-fit acetabular cup with a dual mobility liner and a 17 × 300 mm diaphyseal-engaging monoblock tapered fluted titanium stem with cerclage stabilization. Her post-operative course was notable for a single posterior dislocation managed with closed reduction. At the latest follow-up 4 months postoperatively, she demonstrated stable reconstruction without recurrent infection. Conclusion: Fixation failure of subtrochanteric femur fractures combined with early post-operative infection can lead to profound proximal femoral bone loss. This case demonstrates successful management using a two-stage approach with aggressive debridement, static antibiotic spacer placement, and definitive revision THA in the setting of acquired extensive proximal femoral bone loss.