Proposition d’un protocole de suivi des infections avérées de site opératoire en chirurgie orthopédique et traumatologique

Differences in Diagnostic Properties Between Standard and Enrichment Culture Techniques Used in Periprosthetic Joint Infections

BACKGROUND

Culture-negative infections can complicate the diagnosis and management of orthopedic infections, particularly periprosthetic joint infections (PJIs). This study aimed to identify differences in rate of detection of infection and organisms between cultured using standard and enriched methods.

METHODS

This retrospective, cross-sectional study evaluated PJI samples obtained between January 2013 and December 2017 at Yokohama City University Hospital. Samples were assessed using standard and enrichment culture techniques. White blood cell counts, C-reactive protein levels, type of microorganism (coagulase-positive or coagulase-negative), and methicillin-resistant Staphylococcus were investigated.

RESULTS

A total of 151 PJI samples were included in the analysis; of these, 68 (45.0%) were positive after standard culture while 83 (55.0%) were positive only after enrichment culture. The mean white blood cell counts and C-reactive protein levels were significantly lower in the enrichment culture group than in the standard culture group (P < .01). The rate of methicillin-resistant Staphylococcus and coagulase-negative Staphylococci was significantly higher in the enrichment culture group than in the standard culture group (P < .01).

CONCLUSION

The enrichment culture method has a higher rate of detection of infection than standard culture techniques and should, therefore, be considered when diagnosing orthopedic infections, particularly PJI.

Variation in the Type and Frequency of Postoperative Invasive Staphylococcus aureus Infections According to Type of Surgical Procedure

Objective.

To determine the epidemiological characteristics of postoperative invasive Staphylococcus aureus infection following 4 types of major surgical procedures.

Design.

Retrospective cohort study.

Setting.

Eleven hospitals (9 community hospitals and 2 tertiary care hospitals) in North Carolina and Virginia.

Patients.

Adults undergoing orthopedic, neurosurgical, cardiothoracic, and plastic surgical procedures.

Methods.

We used previously validated, prospectively collected surgical surveillance data for surgical site infection and microbiological data for bloodstream infection. The study period was 2003 through 2006. We defined invasive S. aureus infection as either nonsuperficial incisional surgical site infection or bloodstream infection. Nonparametric bootstrapping was used to generate 95% confidence intervals (CIs). P values were generated using the Pearson x2 test, Student t test, or Wilcoxon rank-sum test, as appropriate.

Results.

In total, 81,267 patients underwent 96,455 procedures during the study period. The overall incidence of invasive S. aureus infection was 0.47 infections per 100 procedures (95% CI, 0.43–0.52); 227 (51%) of 446 infections were due to methicillin-resistant S. aureus. Invasive S. aureus infection was more common after cardiothoracic procedures (incidence, 0.79 infections per 100 procedures [95% CI, 0.62–0.97]) than after orthopedic procedures (0.37 infections per 100 procedures [95% CI, 0.32–0.42]), neurosurgical procedures (0.62 infections per 100 procedures [95% CI, 0.53–0.72]), or plastic surgical procedures (0.32 infections per 100 procedures [95% CI, 0.17¬0.47]) (P < .001). Similarly, S. aureus bloodstream infection was most common after cardiothoracic procedures (incidence, 0.57 infections per 100 procedures [95% CI, 0.43–0.72]; P < .001, compared with other procedure types), comprising almost three-quarters of the invasive S. aureus infections after these procedures. The highest rate of surgical site infection was observed after neurosurgical procedures (incidence, 0.50 infections per 100 procedures [95% CI, 0.42–0.59]; P < .001, compared with other procedure types), comprising 80% of invasive S. aureus infections after these procedures.

Conclusion.

The frequency and type of postoperative invasive S. aureus infection varied significantly across procedure types. The highest risk procedures, such as cardiothoracic procedures, should be targeted for ongoing preventative interventions.

Incidence of surgical-site infections in orthopaedic surgery: a northern Italian experience

A prospective cohort study with a 1-year telephone follow-up was performed to estimate the incidence of surgical-site infections (SSIs) in hip and knee prostheses. Twenty-five public hospitals equipped with orthopaedic units in two Italian regions were involved. An 8-month surveillance period was set to obtain significant data at a regional level and data were collected by the infection control nurses of each centre. One-year follow-up was completed in 75% of cases. SSIs were recorded in 45 cases (incidence rate 1·9/100 person-years, 95% CI 1·4–2·5). Thirty-six percent of SSIs were diagnosed during hospitalization and 95·3% within 90 days post-operation. This incidence is similar to that reported by European and USA surveillance systems. The proposed investigative method proved to be reliable and feasible. A prolonged surveillance for at least 3 months post-operation yields a good estimate of SSI in joint replacements.