Antibiotic Prophylaxis for ORIF Procedures
For ORIF of closed extremity fractures, administer cefazolin 2g IV (or 1g for patients <80kg) within 60 minutes before incision, with re-dosing every 4 hours intraoperatively if needed, and discontinue within 24 hours after wound closure. 1, 2
First-Line Antibiotic Selection
Cefazolin is the antibiotic of choice for ORIF procedures, providing excellent coverage against Staphylococcus aureus, Staphylococcus epidermidis, streptococci, and common gram-negative organisms that cause surgical site infections in orthopedic surgery 3, 1
The standard dose is 2g IV for patients ≥80kg or 1g IV for lighter patients, administered as a slow infusion 30-60 minutes before surgical incision 3, 2
Re-inject 1g of cefazolin if surgical duration exceeds 4 hours to maintain therapeutic levels throughout the procedure 1, 2
Duration of Prophylaxis
Limit antibiotic prophylaxis to a single preoperative dose or maximum 24 hours postoperatively - extending beyond this timeframe does not reduce infection rates and increases antibiotic resistance 4, 5, 6
High-quality randomized controlled trial evidence demonstrates no significant difference in surgical site infection rates between 23-hour postoperative cefazolin versus placebo (9.4% overall infection rate with no difference between groups) 4
For prosthetic arthroplasty or particularly high-risk cases, prophylaxis may be extended to 3-5 days following surgery, though this is reserved for exceptional circumstances 2
Alternative Regimens for Beta-Lactam Allergy
For severe beta-lactam allergies, use vancomycin 30mg/kg IV infused over 120 minutes (based on actual body weight), started within 60 minutes before incision 3, 1
Vancomycin should be dosed carefully to avoid nephrotoxicity and requires slower infusion to prevent red man syndrome 3
Special Considerations for Open Fractures
Open fractures require different management than closed fractures undergoing ORIF - for Gustilo-Anderson type I/II open fractures, use first-generation cephalosporin alone; for type III, add an aminoglycoside for enhanced gram-negative coverage 1
For wounds with gross contamination, add penicillin to cover anaerobic organisms even in lower-grade fractures 1
Local antibiotic delivery systems (gentamicin-coated implants, antibiotic-impregnated beads) serve as beneficial adjuncts for severe type III fractures with bone loss 1
Dosing Adjustments
Adjust cefazolin dosing for renal impairment: patients with creatinine clearance 35-54 mL/min can receive full doses at 8-hour intervals; those with CrCl 11-34 mL/min should receive half the usual dose every 12 hours 2
Weight-based dosing is critical - ensure adequate tissue concentrations in obese patients by using actual body weight for calculations 4
Risk Stratification
Patients with diabetes mellitus have 4.33 times higher risk of surgical site infection (95% CI 1.30-14.38) and may warrant closer monitoring, though this does not justify extended antibiotic duration 4
Male sex and fracture fixation device infections independently predict reinfection (OR 2.06 and 2.05 respectively), but again, this supports meticulous surgical technique rather than prolonged antibiotics 7
Common Pitfalls to Avoid
Do not routinely extend prophylaxis beyond 24 hours - multiple studies confirm this increases costs and resistance without reducing infection rates 4, 5, 6, 8
Do not add routine MRSA coverage with vancomycin unless institutional epidemiology specifically warrants it - cefazolin alone is sufficient for most clean orthopedic procedures 1
Ensure preoperative timing is correct - antibiotics given too early (>60 minutes) or too late lose effectiveness 2
Do not confuse prophylaxis with treatment - if infection develops postoperatively, switch to culture-directed therapeutic antibiotics rather than continuing prophylactic regimens 4, 5