Analysis of Causative Microorganism in 248 Primary Hip Arthroplasties Revised for Infection: A Study Using the NJR Dataset

Introduction This study aimed to describe the epidemiology of the causative organism in a series of primary hip arthroplasties revised for a diagnosis of periprosthetic joint infection (PJI) in England and Wales. Methods Patient data from the National Joint Registry (NJR) was linked to microbiology data held by Public Health England (PHE) which identified a series of 248 primary hip arthroplasties revised for PJI between 2003 and 2014. Definitive cultures, isolated at time of revision surgery, were available for all cases. Total hip arthroplasty (n = 239, 96%) and hip resurfacing (n = 5, 2%) were the most commonly performed primary procedures. A two-stage revision was the most common operative management (n = 174, 70%). Results 202 (81%) cases were infected with a single genus microorganism and the most commonly implicated genus was Staphylococcus species (70% of all single genus infections). Staphylococcus species were also the most commonly identified microorganism in mixed genus infections (74% of patient's cultures). There was a significant difference in microorganism distribution when comparing uncemented vs cement implant fixation, with a higher incidence of Gram-negative infection observed in the uncemented group (p = 0.048, Chi-square). Conclusions Both prophylactic and therapeutic antibiotic regimes should be focused on targeting Staphylococci.