Background: A total lockdown for pandemic SARS-CoV-2 (Covid-19) entailed a restriction of elective orthopedic surgeries in Switzerland. While access to the hospital and human contacts were limited, hygiene measures were intensified. The objective was to investigate the impact of those strict public health guidelines on the rate of intra-hospital, deep surgical site infections (SSI), wound healing disorders and non-infectious postoperative complications after orthopedic surgery during the first Covid-19 lockdown. Methods: In a single-center study, patients with orthopedic surgery during the first Covid-19 lockdown from March 16, 2020 to April 26, 2020 were compared to cohorts that underwent orthopedic intervention in the pre- and post-lockdown periods of six months each. Besides the implementation of substantial public health measures (promotion of respiratory etiquette and hand hygiene), no additional infection control bundles have been implemented. Results: 5791 patients were included in this study. In multivariate Cox regression analyses adjusting for the large case-mix, the lockdown was unrelated to SSI (hazard ratio (HR) 1.6; 95% confidence interval (CI) 0.6–4.8), wound healing disorders (HR 0.7; 95% CI 0.1–5.7) or other non-infectious postoperative complications (HR 0.7, 95% CI 0.3–1.5) after a median follow-up of seven months. Conclusion: The risks for SSI, wound healing disorders and other complications in orthopedic surgery were not influenced by the extended public health measures of the total Covid-19 lockdown. Trial registration BASEC 2020–02646 (Cantonal Ethics Commission Zurich). Level of evidence: Level III.

Surgical site infection (SSI) after elective orthopedic foot and ankle surgery is uncommon and may be higher in selected patient groups. Our main aim was to investigate the risk factors for SSI in elective orthopedic foot surgery and the microbiological results of SSI in diabetic and non-diabetic patients, in a tertiary foot center between 2014 and 2022. Overall, 6138 elective surgeries were performed with an SSI risk of 1.88%. The main independent associations with SSI in a multivariate logistic regression analysis were an ASA score of 3–4 points, odds ratio (OR) 1.87 (95% confidence interval (CI) 1.20–2.90), internal, OR 2.33 (95% CI 1.56–3.49), and external material, OR 3.08 (95% CI 1.56–6.07), and more than two previous surgeries, OR 2.86 (95% CI 1.93–4.22). Diabetes mellitus showed an increased risk in the univariate analysis, OR 3.94 (95% CI 2.59–5.99), and in the group comparisons (three-fold risk). In the subgroup of diabetic foot patients, a pre-existing diabetic foot ulcer increased the risk for SSI, OR 2.99 (95% CI 1.21–7.41), compared to non-ulcered diabetic patients. In general, gram-positive cocci were the predominant pathogens in SSI. In contrast, polymicrobial infections with gram-negative bacilli were more common in contaminated foot surgeries. In the latter group, the perioperative antibiotic prophylaxis by second-generation cephalosporins did not cover 31% of future SSI pathogens. Additionally, selected groups of patients revealed differences in the microbiology of the SSI. Prospective studies are required to determine the importance of these findings for optimal perioperative antibiotic prophylactic measures.

Background/Objectives: In orthopedic (diabetic) foot surgery, the serum C-reactive protein (CRP) is frequently measured not only as a diagnostic tool, but also as a control inflammatory marker in the follow-up of operated surgical site infections (SSI) Methods: We investigate the predictive value of the post-debridement routine (control) serum CRP level in adult (diabetic) patients with SSI in the foot. We exclude community-acquired (diabetic foot) infections and focus on the predictive accuracy of routine (control) CRP measurements in terms of ultimate therapeutics failures. Results: The median pre- and postoperative CRP were 25 mg/L and 8.8 mg/L, respectively. In group comparisons and multivariate assessment, neither the immediate (relative and absolute) drop of the serum CRP level, nor its values between 5 and 8 weeks and between 11 and 14 weeks predicted the failure risk of 19%. In contrast, in cases of a surprisingly elevated CRP levels, this finding leads to unnecessary radiological, clinical and laboratory exams during clinical treatment of infections. Conclusions: Routine, postoperative CRP monitoring during the treatment of established (diabetic) foot SSIs is futile, unnecessarily costly, and should be avoided in favor of a clinical surveillance of the postoperative evolution.

Background/Objectives: In orthopedic (diabetic) foot surgery, the serum C-reactive protein (CRP) level is frequently measured not only as a diagnostic tool, but also as a control inflammatory marker in the follow-up of postoperative surgical-site infections (SSIs) Methods: We investigated the predictive value of the post-debridement routine (control) serum CRP level in adult (diabetic) patients with an SSI in the foot. We excluded community-acquired (diabetic foot) infections and focused on the predictive accuracy of routine (control) CRP measurements in terms of ultimate therapeutic failures. Results: The median pre- and postoperative CRP levels were 25 mg/L and 8.8 mg/L, respectively. In group comparisons and multivariate assessment, neither the immediate (relative and absolute) drop in the serum CRP level, nor its values between 5 and 8 weeks and between 11 and 14 weeks predicted the failure risk of 19%. In contrast, in cases of surprisingly elevated CRP levels, this finding leads to unnecessary radiological (median costs approximatively USD 200), clinical, microbiological urinary sample (median costs USD 50), and laboratory (one CRP sample USD 10) exams. These additional exams also likely prolong the duration of hospitalization by one to two days (e.g., whilst awaiting the microbiological results) and often generate unnecessary consultations among internist and/or infectious diseases experts (USD 50). Conclusions: Routine, postoperative CRP monitoring during the treatment of established orthopedic (diabetic) foot SSIs is unnecessarily costly, and should be avoided in favor of clinical surveillance of the postoperative evolution.