Background/Objectives: Almost all orthopedic infections require a combination of surgical debridement with targeted antimicrobial treatment. The number of debridement procedures may vary considerably between infection episodes. The case mix is large, and so-called “second looks” are frequent. We investigate which bacteria are associated with second looks to achieve local infection control. Methods: We used a composite database stemming from three prospective randomized controlled trials (RCTs) from 2019 to 2025 with protocoled surgical debridement (initial debridement). In these RCTs, we allowed additional debridement only in the case of persistent or progressive local infection. Results: Overall, 201/1067 (18.8%) orthopedic infections required multiple debridement procedures. The median number of additional debridement procedures was two across all pathogen groups, with a range of 2–8 interventions. Gram-negative pathogens revealed the highest risk for “second looks” (28.2%), followed by implant-related infections (25.4%). Cutibacteria yielded the lowest risk (11.7%). In the multivariable logistic regression model, Gram-negative infections (OR 2.04, 95%CI 1.20–3.47) and infected implants (OR 2.18, 95%CI 1.56–3.03) were independently associated with multiple interventions, in contrast to Staphylococcus aureus, Enterococci, or Streptococci. Conclusions: Gram-negative pathogens were significantly associated with the need for second looks in orthopedic infections. The findings support preoperative counseling, antibiotic stewardship, and operative planning for staged management in infection cases with a high risk of clinical failure. Trials registrations: NCT04048304, NCT04081792, NCT05499481.

Background/Objectives: Almost all orthopedic infections require a combination of surgi-cal debridement with targeted antimicrobial treatment. The number of debridement may vary considerably between infection episodes. The case-mix is enormous and so-called "second looks" are frequent. We investigate which bacteria are associated with second looks to achieve local infection control. Methods: We used a composite database stem-ming from three prospective randomized-controlled trials (RCTs) 2019-2025 with proto-colled surgical debridement (initial debridement). In these RCTs, we allowed additional debridement only in case of persistent (during several days) or progredient local infection. Results: Overall, 201/1,067 (18.8%) orthopedic infections required multiple debridement (median two second looks, range 2–8 surgeries). Gram-negative pathogens revealed the highest risk for "second looks" (28.2%), followed by implant-related infections (25.4%). Cutibacteria yielded the lowest risk (11.7%). In the multivariable logistic regression model, Gram-negative infections (odds ratio 2.04, 95%CI 1.20-3.47) and infected implants (OR 2.18, 95%CI 1.56-3.03) were independently associated to multiple interventions, in con-trast to Staphylococcus aureus, enterococci or streptococci. Conclusions: When analyzing orthopedic infections included in prospective RCTs, Gram-negative pathogens groups significantly associate with the need for second looks, which matches our own experience. Today findings support preoperative counseling, antibiotic stewardship, and operative planning for a staged management in infection cases with a high risk of clinical failure. Trials registrations: NCT04048304, NCT04081792, NCT05499481.

Background/Objectives: In staphylococcal implant infections, there is often discussion about the optimal postoperative timing of the introduction of rifampicin in the postoperative period with open wounds. Methods: We reviewed all adult patients with residual staphylococcal implant infections between January 2014 and May 2024. We analyzed the delay to rifampicin use in relation to therapeutic failures, infection recurrences, and development of ultimate rifampicin resistance. Results: Among 103 independent infection episodes, 47 (46%) contained the pathogen S. aureus, and the remainder were different coagulase-negative staphylococci. The median number of surgical interventions was one, and the median duration of postsurgical systemic antibiotic treatment was 84 days (interquartile range (IQR), 42–84 d). The median daily dose of oral rifampicin was 900 mg, and the median delay in its introduction was 5 days (IQR, 3–8 d). Overall, 18% of patients experienced an adverse event related to rifampicin (mostly gastrointestinal), requiring treatment to be stopped. The incidences of clinical failures and of microbiologically identical recurrences were 27% and 10%, respectively. The risk of rifampin resistance among any new staphylococcal infection or colonization during a median follow-up of 1.9 years was 1%. In the multivariate Cox regression analysis, the delay in rifampicin administration, its dose, or its duration failed to alter outcomes. Conclusions: In our retrospective cohort of staphylococcal orthopedic implant infections, the timing of rifampicin introduction failed to alter clinical and microbiological outcomes.

Background/Objectives: In staphylococcal implant infections, there is often discussion about the optimal postoperative timing of the introduction of rifampicin in the postoperative period with open wounds. Methods: We reviewed all adult patients with residual staphylococcal implant infections between January 2014 and May 2024. We analyzed the delay to rifampicin use in relation to therapeutic failures, infection recurrences and development of ultimate rifampicin resistance. The “last Staphylococcus” represented any clinical sample at the end of the individual period. Results: Among 103 independent infection episodes, the pathogens were S. aureus in 47 episodes (46%) and the remainder were different coagulase-negative staphylococci. The median number of surgical interventions was 1 and the median duration of postsurgical systemic antibiotic treatment was 84 days (interquartile range (IQR), 42-84 d). The median daily dose of oral rifampicin was 900 mg, the median delay of its introduction 5 days (IQR, 3-8 d). Overall, 13% experienced an adverse event related to rifampicin (mostly gastrointestinal), requiring its stopping. The incidences of Clinical Failures and of Microbiologically identical Recurrences were 27% and 10%, respectively. The risk of rifampin-resistance among the “last Staphylococcus” isolates was 1%. This single case occurred in an infected knee to which rifampicin was introduced after a delay of eight days. In multivariate Cox regression analysis, the delay of rifampicin administration, its dose or its duration all failed to alter outcomes. Conclusions: In our retrospective cohort of staphylococcal orthopedic implant infections, the timing of rifampicin introduction failed to alter clinical and microbiological outcomes.

Background: With an ever-increasing population of elderly orthopedic patients experiencing co-morbidities and immune suppression, the proportion of postoperatively acquired surgical site infections (SSIs) may increase compared to prior decades, where the majority of SSIs were acquired intraoperatively. A comprehensive overview would aid in allocating resources under these conditions. Methods: We examined a prospective database containing data from four prospective randomized clinical interventional trials and surveillance registers. We concentrated on cases of acute SSIs with complete documentation from the 2019–2024 period, during which the number and proportion of clinically frail patients treated at our tertiary center increased significantly. In this assessment, surgeons and Infectious Physicians specialized in orthopedic infections evaluated each SSI episode clinically by searching medical and nursing notes for postoperative events that could possibly be associated with postoperative surgical site infection. Results: Among 370 SSI cases, we estimated that 241 infections (65%) were acquired intraoperatively and 129 (35%) postoperatively. The three most frequent reasons for postoperative SSIs were skin breakdowns, surgical complications (hematoma; dehiscence), and ischemic necrosis. These (new) risk associations differed significantly from the SSI risk reported in the literature on middle-aged orthopedic patients. Conclusions: According to our prospective evaluation, one-third of acute orthopedic SSIs in the last six years might be associated with a postoperative complication. We need to implement additional preventive measures in the postoperative period.