Surgical approaches in total hip arthroplasty do not influence the bacterial spectrum of acute postoperative periprosthetic joint infections

<b>Introduction</b>: With the increasing number of primary total hip arthroplasties (THAs), the incidence of associated complications has risen, with periprosthetic joint infection (PJI) being among the most severe. The influence of surgical approach on infection risk remains debated; however, its effect on the microbiological profile of PJIs is not well examined. This study aimed to evaluate whether the primary surgical approach affects the spectrum of microorganisms involved in acute postoperative periprosthetic hip joint infections in a retrospective single-center cohort. <b>Methods</b>: A total of 76 patients who underwent revision surgery for PJI following THA between January 2013 and June 2024 were retrospectively reviewed. After applying exclusion criteria, patients were categorized based on the initial surgical approach: lateral vs. direct anterior/anterolateral. The microbiological spectrum was compared between groups using Fisher's exact test. Demographic characteristics and their associations with surgical approach and pathogen type were also analyzed. <b>Results</b>: No significant differences were found in the microbiological spectrum between surgical approaches. Similarly, there was no significant correlation between surgical approach and the occurrence of Gram-positive or Gram-negative organisms. Body mass index (BMI) was not associated with variations in pathogen distribution, suggesting that obesity does not influence the microbiological profile of PJI. <b>Discussion</b>: These findings suggest that the microbiological characteristics of acute postoperative PJI are independent of the primary surgical approach. Minimally invasive anterior techniques do not appear to carry an increased microbiological risk. Additionally, BMI does not influence the microbial spectrum of infection. <b>Level of evidence</b>: this is a retrospectively registered cohort study with a Level III level of evidence.