Antibiotic prophylaxis aims to reduce wound and prosthetic infection, with minimal adverse effects. The 3 dose Cefuroxime regime is widely used, despite the risk of infective diarrhoea. We describe the results of single dose intraoperative Gentamicin and Amoxicillin compared to this standard regime.

We retrospectively reviewed 220 patients following hip hemiarthroplasty, creating 2 demographically matched cohorts; Group 1: 3 doses of Cefuroxime (n=113) and Group 2: single dose Gentamicin and Amoxicillin (n=107). End points were evidence of infection, length of stay and Clostridium difficile (CD) rates. results showed a significant reduction in group 2 for average length of stay (17 Vs. 13 days p=0.0432) and CD rates (7/113 Vs 0/107 p=0.0158).

Considering antibiotic therapies administered; significant reductions in group 2 for the number of patients that required post-operative antibiotics (99/113 Vs 73/107 p=0.0005), the median antibiotic DDDs (Defined Daily Doses) in 1st 2 post-operative days (0.25 Vs 0 p=0.0000) and those that received Ciprofloxacin or Cefuroxime post-operatively (82/113 Vs 24/107 p=0.0000). No significant difference was found for median antibiotic DDDs, median antibiotic DDDs from 2nd post-operative day, patients that received Flucloxacillin post-operatively.

Measured microbiological outcomes showed a significant reduction in the number of patients with confirmed growth requiring treatment with antibiotics in group 2 (21/23 Vs 12/22 p=0.0053). No difference was found between number patients with operation site swabbed and those with confirmed microbial growth.

We demonstrate single dose Gentamicin and Amoxicillin significantly reduces length of stay, CD rates and the number of patients requiring post-operative antibiotics for wound infection, inferring a reduction in the rate of wound infection. We would recommend this as an effective alternative to the 3 dose Cefuroxime regime.

Objective: To identify institution specific risk factors for developing MRSA surgical site infection (SSI) and develop an objective mechanism to estimate the probability of MRSA infection in a given patient admitted to the orthopaedic unit.

Design: A cohort study was performed to identify risk factors in all patients who had MRSA infection during admission on the orthopaedic unit between January 2002 and December 2004. Logistic regression was used to model the likelihood of MRSA. A stepwise approach was employed to derive a model. The MRSA prediction tool was developed from the final model.

Results: Of the 11 characteristics included in the logistic regression, the features that strongly predicted a MRSA infection were ASA grade, patient’s residence and reason for admission.

110 had MRSA infection in their surgical wound. 83 of 110 (75.5%) patients were non-elective admissions, of which 49 (60%) were proximal femur fractures. 20% of proximal femur fractures admitted from nursing home and 7.8% from their own homes developed SSI with MRSA. This cohort of SSI with MRSA had an average of 5.7(1–18) previous admissions. 25 (23%) had been previously colonised with MRSA. Majority of them (76%) were between 70–90 years old and were ASA grade 3–4.

Conclusion: Through multivariate modelling technique we were able to identify the most important determinants of patients developing SSI with MRSA in our institute and develop a tool to predict the probability of MRSA in a given patient. This knowledge can be used to guide the use of appropriate prophylactic antibiotic and to take other required measures to avoid the SSI with MRSA.