Surgical Approach and Microbiologic Trends in Hip Periprosthetic Joint Infection: A Retrospective Comparison of Anterior and Posterior THA.

Abstract

Periprosthetic joint infection (PJI) is a serious complication after total hip arthroplasty (THA). Previous work has explored risk factors of infection, but few studies have evaluated whether surgical approach influences the microbiologic profile of THA PJIs. A retrospective review identified patients who developed PJI after primary THA between January 2007 and January 2024. The surgical approach (direct anterior vs. posterior) was determined from surgical reports. Infecting organisms were categorized as gram-positive, gram-negative, polymicrobial, or culture-negative. Clinical and microbiologic variables were compared between approaches. Among culture-positive, microbiologically homogeneous infections, multivariable logistic regression assessed the association between approach and gram-negative infection. Eighty-three patients met inclusion criteria: 22 with anterior and 61 with posterior THAs. No significant differences were observed in age, sex, body mass index, Charlson Comorbidity Index, or SIRS score between cohorts (P > 0.05). Organism profiles were broadly similar across groups, with no statistically significant differences in specific pathogens or microbiologic categories, including gram-positive, gram-negative, or culture-negative PJIs. Although not statistically significant, polymicrobial infections were more common in the posterior cohort (13.1 vs. 4.5%, P = 0.433) and gram-negative organisms in the anterior cohort (18.2 vs. 4.9%, P = 0.076). On multivariable analysis, the surgical approach trend toward gram-negative infections remained but was not statistically significant (OR, 3.79; 95% CI, 0.74 to 19.34; P = 0.110). The surgical approach was not associated with significant differences in the infecting organism profile after THA PJI. However, the observed trend toward more gram-negative infections with the anterior approach warrants additional investigation.