SA Orthopaedic Journal
On-line version ISSN 2309-8309
GOLLER, R et al. Prosthesis sepsis in a tertiary setting: a retrospective analysis. SA orthop. j. [online]. 2010, vol.9, n.2, pp. 83-87. ISSN 2309-8309.
PURPOSE OF THE STUDY: Annually, more than a million joint replacements are performed worldwide. The most feared complication is infection. The purpose of this study is to establish the spectrum of organisms and their respective sensitivities, cultured during primary and secondary debridements of staged revision surgery. These findings were then utilised to suggest alternative empiric antimicrobial therapy. DESCRIPTION OF METHODS: A retrospective analysis was performed on patients undergoing revision hip or knee arthroplasty at a tertiary hospital in South Africa from June 2005 to March 2009. Only patients in whom intra-operative deep microbiological cultures had been performed were included. SUMMARY OF RESULTS: Deep microbiological cultures were performed in all cases on either joint synovium, fluid or pus swabs taken from the site intra-operatively. Following primary debridement of staged revision surgery, 38% of samples submitted were culture positive from 61 patients, rendering 29 isolates (six double infections). The spectrum was highly variable. Although no methicillin-resistant Staphylococcus aureus (MRSA) was isolated in the initial cultures, the majority of organisms were Gram positive (62%). Fourteen of these patients (23%) required a second debridement; 12 patients had positive cultures (86%), rendering 20 isolates (four double and two triple infections). Gram-negative organisms played a significant role in these patients with the majority of cases culturing multi-resistant organisms. CONCLUSION: Although no MRSA was cultured, vancomycin is widely used as an empiric postoperative antimicrobial. In this setting, 72% of isolates were sensitive to vancomycin; however, co-amoxyclav also covered 72% of isolates, with the benefit of superior efficiency and fewer side effects. We suggest the possible use of co-amoxyclav with rifampicin as a potential first-line antimicrobial in this clinical setting. Multi-drug resistance is increasingly important in patients requiring secondary debridements. In this setting a combination of carbapenems with vancomycin should be considered as empiric postoperative antibiotics, as it covered 75% of organisms in our clinical setting.