Diagnostic dilemma and management of peri-prosthetic joint infection presenting as recurrent dislocation following acetabular fracture fixation: a case report

Abstract

Peri-prosthetic joint infection (PJI) can often mimic mechanical failure or present subtly following trauma. We present a 60-year-old male with a history of bilateral Total Hip Arthroplasty (THR) who presented with pain and inability to walk two months following a road traffic accident. The patient had previously undergone acetabular plating for a fracture-dislocation of the left hip, followed by a recurrent dislocation treated with closed reduction. On presentation, inflammatory markers were raised (ESR 54, CRP 40). Suspecting infection, we did Synovial fluid aspiration that revealed frank purulence with a WBC count >30,000/mm³ and 99% neutrophils. As per MSIS 2018 Criteria our case had ->6 score. The patient was diagnosed with PJI and underwent a first-stage revision arthroplasty involving implant removal, thorough debridement, and insertion of an antibiotic-loaded cement spacer with absorbable antibiotic beads. This case highlights the importance of ruling out infection in cases of recurrent dislocation and aseptic loosening, even when a clear history of trauma exists. Pre-operative aspiration remains the gold standard for diagnosis.