Changing antibiotic prophylaxis for primary joint arthroplasty affects postoperative complication rates and bacterial spectrum.

BACKGROUND: The reduction of Clostridium difficile associated diarrhoea (CDAD) is a national priority. As part of the C. difficile improvement plan in our Trust, antibiotic prophylaxis for primary arthroplasty was changed from cefuroxime to gentamicin. Gentamicin was chosen following a review of the sensitivity profiles of all the organisms isolated from infected primary arthoplasties.
METHODS: From January 2002 to September 2007, 6094 patients (Group 1) undergoing primary hip and knee arthroplasty received three doses of Cefuroxime as prophylaxis; while from October 2007 to February 2009, 2101 patients (Group 2) received single dose Gentamicin (4.5 mg/kg). We studied the rate of CDAD as well as several other postoperative complications, including rate of return to theatre (RTT), before and after the change.
FINDINGS: There was an insignificant fall in CDAD from 0.18% to 0% (p=0.08) in Group 2, however there was a statistically significant increase in pneumonia (0.67-1.33%, p<0.01), acute renal failure (ARF) requiring HDU admission (0.07-0.33%, p<0.01) and RTT (1.08-1.95%, p<0.01) in this group. RTT for proven infection increased from 0.66% to 1.52% (p<0.01).
CONCLUSIONS: We conclude that Gentamicin 4.5 mg/kg alone should not be used as prophylaxis for primary joint arthroplasty as it does not reduce CDAD significantly but increases the risk of other postoperative complications. We have changed our prophylaxis to low dose gentamicin (3 mg/kg) combined with Teicoplanin 400 mg given once.