[Improving microbiological diagnostics in septic orthopaedic surgery. Comparative study of patients receiving systemic antibiotic therapy].

MATERIAL AND METHODS: This prospective study included 63 patients with confirmed infections of soft tissue, joints, bones or implants. During 110 surgical interventions, 124 swab and deep tissue sample pairs were taken and analysed microbiologically using standard procedures.
RESULTS: In 40 patients who had not received prior antibiotic treatment, 57 sample pairs (swabs/tissue) were taken. In 70%, growth of microorganisms could be observed in both swabs and tissue samples. Growth in tissue sample only was observed in 14% and in 14% no growth could be detected. In 67 sample pairs taken from 23 patients who had received systemic antimicrobial treatment prior to surgery, microbial growth in both specimens was detected in 40%. Growth in tissue sample only was observed in 22% and 34% of the samples remained without detectable growth. The overall sensitivity of the tissue samples (70%) was significantly higher than in swab samples (44%) for the pretreated group.
CONCLUSION: The use of intraoperative tissue samples for microbiological diagnostics in septic orthopaedic surgery must be considered a "gold standard". The higher sensitivity of intraoperative tissue samples is particularly important in patients receiving systemic antibiotic therapy prior to surgical interventions.