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Updated: May 28, 2026
11:17
Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses
Published on: August 30, 2018
Are bone and serum cefazolin concentrations adequate for antimicrobial prophylaxis?
Koji Yamada1, Kunihiro Matsumoto, Fumiaki Tokimura
1Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. forpatients2008@gmail.com
Clinical Orthopaedics and Related Research
|October 5, 2011
Summary
Two grams of cefazolin effectively reached serum and bone concentrations against methicillin-sensitive Staphylococcus aureus. However, bone concentrations did not reach the minimum inhibitory concentration for cefazolin-resistant coagulase-negative Staphylococcus, posing a potential infection risk.
Area of Science:
- Orthopaedic Surgery
- Infectious Disease
- Pharmacokinetics
Background:
- Surgical-site infections (SSIs) are a concern in clean orthopaedic surgery.
- Antimicrobial prophylaxis aims to prevent SSIs.
- The efficacy of cefazolin tissue concentrations against specific pathogens remains unclear.
Purpose of the Study:
- To determine if a 2g cefazolin dose achieves adequate serum and bone concentrations.
- To compare these concentrations against the minimum inhibitory concentration (MIC) for key Staphylococcus species.
- To assess the risk of SSIs in hip and knee arthroplasty.
Main Methods:
- 43 patients undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) were enrolled.
- A 2g intravenous dose of cefazolin was administered pre-incision.
- Serum and bone samples were collected and analyzed for cefazolin concentrations.
- MIC values were based on national data.
Main Results:
- Mean serum cefazolin concentration was 170.3 μg/mL.
- Mean bone concentrations were 32.3 μg/g (THA) and 16.0 μg/g (TKA).
- All samples exceeded the MIC for methicillin-sensitive S. aureus; however, bone concentrations did not meet the MIC for cefazolin-resistant coagulase-negative Staphylococcus.
Conclusions:
- Cefazolin at 2g achieves effective concentrations against methicillin-sensitive S. aureus in serum and bone.
- Bone concentrations are insufficient against cefazolin-resistant coagulase-negative Staphylococcus.
- This may increase the risk of deep SSIs in THA and TKA procedures.
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