Trauma-Related Arthroplasty Is Associated With Earlier and Microbiologically Distinct Periprosthetic Joint Infection: A 20-Year Single-Center Study.

BACKGROUND: Periprosthetic joint infection (PJI) following arthroplasty performed for trauma (e.g., hip fracture) may differ from PJI after elective arthroplasty in terms of timing, microbiology, and outcomes, but comparative data remain limited.

METHODS: We conducted a 20-year single-center retrospective cohort study (2003 to 2023) at a tertiary referral hospital, of which 41 (20%) followed trauma-related arthroplasty and 162 (80%) followed elective procedures. Adults diagnosed with PJI were identified using Hospital In-Patient Enquiry coding (ICD-10 T84.5) and an infectious diseases outpatient parenteral antimicrobial therapy database, with chart confirmation. The primary outcome was treatment success ("cure") at 12 months, defined as cessation of antimicrobial therapy, functional restoration of the prosthetic joint, and no evidence of recurrent infection. The main exposure was arthroplasty indication (trauma versus elective). Analyses included descriptive statistics, Kaplan-Meier analysis for time from arthroplasty to infection, and multivariable logistic regressions for cure.

RESULTS: Trauma cases had a lower body mass index (median 26 versus 29, P = 0.004) and occurred earlier, with a median time from arthroplasty to infection of 12 weeks compared with 56 weeks in elective cases (log-rank Chi-square 27.5, P = 0.001). Microbiology differed: gram-negative organisms (26.8 versus 8.6%, P = 0.0042), Enterococcus species (19.5 versus 0.6%, P = 0.045), and Candida species (9.8 versus 1.2%, P = 0.004) were more frequent after trauma, whereas Streptococci were identified only in elective cases (17.3 versus 0%, P = 0.004). The six-month mortality was higher after trauma (17 versus 5%, P = 0.014). The cure at 12 months did not differ significantly (51 versus 60%, P = 0.281). In adjusted analyses, increasing age reduced odds of cure, whereas two-stage revision increased odds; trauma-related arthroplasty was not an independent predictor.

CONCLUSIONS: Trauma-related PJI represents a distinct phenotype with earlier onset, different pathogen spectrum, and higher early mortality, supporting tailored perioperative management in trauma arthroplasty.