What antibiotic (abx) is best for prophylaxis after orthopedic (ortho) surgery?

From the Guidelines

The best antibiotic after orthopedic surgery is typically cefazolin, a first-generation cephalosporin, administered at 2g IV slow, with re-injection of 1g if duration is more than 4 hours, limited to the operative period (24 hours max) 1.

Key Considerations

• The choice of antibiotic should be based on its effectiveness against common orthopedic wound pathogens, particularly Staphylococcus aureus and Staphylococcus epidermidis 1.
• For patients with beta-lactam allergies, clindamycin (900 mg IV slow) or vancomycin (30 mg/kg/120 min) are appropriate alternatives 1.
• Prophylactic antibiotics should be initiated within 60 minutes before surgical incision and discontinued within 24 hours after surgery for most orthopedic procedures to minimize surgical site infections while preventing antibiotic resistance.
• Weight-based dosing adjustments should be made for obese patients, and renal dosing adjustments may be required for those with kidney impairment.

Specific Recommendations

• For joint prosthesis (upper limb, lower limb), cefazolin is recommended at 2g IV slow, with re-injection of 1g if duration is more than 4 hours, limited to the operative period (24 hours max) 1.
• For spine surgery with implantation of prosthetic material, cefazolin is recommended at 2g IV slow, with single dose (if duration > 4h reinject 1g) 1.
• For patients with suspected or proven colonization by methicillin-resistant Staphylococcus, vancomycin is recommended at 30 mg/kg/120 min, with single dose 1.

From the FDA Drug Label

The prophylactic administration of Cefazolin for Injection, USP preoperatively, intraoperatively, and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy and cholecystectomy in high-risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice, or common duct bile stones). The prophylactic administration of Cefazolin for Injection, USP also may be effective in surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty).

Cefazolin (IV) is the recommended antibiotic for post-orthopedic surgery prophylaxis, as it may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures.

• The recommended dose is 1 gram IV or IM administered 1/2 hour to 1 hour prior to the start of surgery.
• For lengthy operative procedures, 500 mg to 1 gram IV or IM during surgery and 500 mg to 1 gram IV or IM every 6 to 8 hours for 24 hours postoperatively may be administered.
• In surgery where the occurrence of infection may be particularly devastating, the prophylactic administration of cefazolin may be continued for 3 to 5 days following the completion of surgery 2.

From the Research

Antibiotic Prophylaxis After Orthopedic Surgery

• The use of cefazolin as a prophylactic antibiotic has been shown to be effective in preventing surgical site infections (SSIs) after orthopedic surgery 3, 4, 5, 6.
• A study published in 2018 found that a single dose of cefazolin 2g, administered 30 minutes before surgery, was associated with a lower rate of SSIs 3.
• Another study published in 2019 found that cefazolin concentrations were higher in the hip than in the knee, suggesting that the dose of prophylactic cefazolin might not be sufficient in distal parts of the extremity 4.
• A 2023 study found that the use of cefazolin as a perioperative antibiotic for infection prophylaxis in total joint arthroplasty in patients labeled beta-lactam allergic is associated with decreased postoperative SSI without an increase in interoperative hypersensitivity reactions 5.
• A 2023 study also found that documented penicillin allergies should not preclude the use of preoperative cefazolin in hip and knee arthroplasty, as the risk of allergic reaction is low 6.
• A 2024 study compared ceftriaxone plus vancomycin versus cefazolin plus gentamicin for antibiotic prophylaxis in grade 3 open fractures, and found that the trend in numerically lower treatment failure rates in the ceftriaxone plus vancomycin group provides sufficient evidence to continue the current local recommendations 7.

Comparison of Antibiotic Regimens

• Cefazolin has been compared to other antibiotic regimens, including clindamycin and vancomycin, and has been found to be effective in preventing SSIs 5, 6.
• A study published in 2023 found that cefazolin was associated with fewer SSIs and prosthetic joint infections compared to clindamycin and/or vancomycin 5.
• Another study published in 2024 found that ceftriaxone plus vancomycin may be associated with lower treatment failure rates compared to cefazolin plus gentamicin, although the difference was not statistically significant 7.

Considerations for Antibiotic Prophylaxis

• The choice of antibiotic prophylaxis should be based on the individual patient's risk factors and medical history 3, 4, 5, 6.
• The use of cefazolin as a prophylactic antibiotic has been shown to be safe and effective in patients with a documented penicillin allergy 5, 6.
• The dose and duration of antibiotic prophylaxis should be tailored to the individual patient's needs and the type of surgery being performed 3, 4.