Characterizing Femoral and Acetabular Bone Loss in Two-Stage Revision Total Hip Arthroplasty for Infection

Background: The process of infection and multiple procedure-related factors in 2-stage exchange arthroplasty may lead to severe bone loss that can complicate subsequent reimplantation. The primary purpose of this study is to quantitatively characterize the extent of bone loss on the femoral and acetabular side prior to reimplantation during 2-stage revision hip arthroplasty for infection.

Methods: This retrospective case series includes 47 patients with planned 2-stage exchange arthroplasty for treatment of infected total hip replacement. Demographic, clinical, and surgical information, and complications during the 2-stage process were collected on all patients. The radiographs of all patients were reviewed prior to first-stage explantation and post-reimplantation or latest follow-up to characterize bone loss using the Paprosky classification systems.

Results: Of the 47 patients with planned 2-stage exchange, 10 patients (21%) were not reimplanted. Following explant and spacer placement, 32 patients (68%) experienced progressive femoral bone loss, and 20 (43%) experienced progressive acetabular bone loss. Patients who experienced progression of both femoral and acetabular bone (14, 30%) had a longer time between resection and reimplantation (164 ± 128 vs 88 ± 26 days, P = .03). A reimplantation time of greater than 90 days was associated with an increased risk of combined bone loss progression (15% vs 53%, P = .01). For patients who underwent reimplantation (79%), increased bone loss led to high rates of diaphyseal femoral fixation (97%) and revision acetabular components (38%).

Conclusion: Increased time to reimplantation in 2-stage exchange arthroplasty for prosthetic hip infections is associated with a high rate of acetabular and femoral bone loss, and increased complexity of reimplantation.