Intraoperative Contamination of Sterile Fields and Postoperative Implications in Total Hip and Knee Arthroplasty: A Prospective Observational Study

Introduction: Periprosthetic joint infections (PJI) are among the most serious and costly complications in orthopedic surgery, significantly affecting patient prognosis and healthcare systems. Despite rigorous aseptic measures, intraoperative contamination of sterile fields, instruments, and air remains a persistent source of potential infection. This study investigates the relationship between the microbial contamination of sterile fields during arthroplasty and postoperative inflammatory markers, with the objective of determining whether the contamination of sterile fields correlates with the presence of periprosthetic joint infection (PJI). Material and Methods: This prospective observational study included 33 patients undergoing total hip or knee arthroplasty in a university-affiliated orthopedic center. Intraoperative samples were collected from sterile fields and equipment to detect microbial contamination, while postoperative monitoring involved the C-reactive protein (CRP); erythrocyte sedimentation rate (ESR); leukocyte count; temperature; and wound assessment on days 1, 3 and 7. All patients received 48 h of prophylactic cefuroxime. Statistical analysis was conducted using the International Business Machines (IBM) Statistical Product and Service Solutions (SPSS) software for Windows, version 30.0 (IBM Corporation, Armonk, New York, United States of America) with significance set at p ≤ 0.05. Results: Postoperative inflammatory markers showed distinct patterns depending on the isolated microorganism, with Proteus vulgaris and Staphylococcus hominis ssp. consistently associated with higher CRP and leukocyte values, indicating a more intense systemic response. Staphylococcus epidermidis was the most frequently isolated species but showed moderate inflammatory profiles, suggesting its potential role in subclinical colonization. A strong correlation between CRP on day 3 and leukocyte count (r = 0.81) confirms their combined utility in the early detection of infectious complications, while ESR appeared less dynamic and more complementary in nature. Discussion: This study highlights the significant role of intraoperative contamination and microbial virulence in shaping the postoperative inflammatory response after arthroplasty. Elevated CRP and leukocyte levels, particularly on day 3, were closely associated with pathogens known for biofilm formation and chronic infections. Despite prophylactic antibiotic use, confirmed infections still occurred, suggesting the need to reassess current protocols and enhance intraoperative contamination control. Conclusions: Pathogen presence in sterile fields during arthroplasty increases the risk of periprosthetic joint infections, often without early clinical symptoms. CRP on day 3 and leukocyte count were the most reliable early indicators of persistent inflammation.