Principles
- Prophylaxis reduces surgical site infection after implant surgery and open fractures
- Based on Australian Therapeutic Guidelines
- Target organisms are Staph aureus and coagulase negative staphylococci
- Giving the dose before incision has more effect than the choice of agent
- Weight based dosing is needed in obesity
Regimen
| Situation | Antibiotic |
|---|---|
| Standard | Cefazolin 2 g IV within 60 minutes before incision. 3 g if 120 kg or more |
| Tourniquet | Give before tourniquet inflation |
| Long surgery | Redose cefazolin after 4 hours |
| Immediate beta-lactam allergy | Clindamycin 600 mg IV, or vancomycin |
| MRSA colonisation | Add vancomycin 15 mg/kg, infusion started within 120 minutes before incision |
Duration
- Single dose for most clean orthopaedic surgery
- Never beyond 24 hours
- Open fractures need early antibiotics within an hour of injury. See Open Fractures
- Prolonged courses raise the risk of C difficile and resistance without lowering infection
- Revision arthroplasty is often given prophylaxis until intraoperative cultures return
- Open fracture regimens differ, see Open Fractures
Other Measures
- Treat skin lesions and dental infection before arthroplasty
- Screen and decolonise MRSA carriers with mupirocin and chlorhexidine
- Chlorhexidine in alcohol skin preparation
- Avoid shaving, use clippers if hair removal is needed
- Keep the patient warm and maintain glycaemic control
Related Pages
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.