Optimizing Vancomycin Soaking Protocols for Anterior Cruciate Ligament Reconstruction.

Area of Science:

• Orthopedic Surgery
• Infectious Disease Prevention
• Biomaterial Science

Background:

• Current anterior cruciate ligament (ACL) autograft guidelines recommend 20-minute vancomycin soaking.
• Clinical settings often limit soaking time to 5 minutes due to practical constraints.
• This study investigates vancomycin efficacy and safety within a 5-minute window.

Purpose of the Study:

• To assess bacterial eradication by vancomycin in ACL autografts within a 5-minute soak.
• To evaluate the cytotoxicity of different vancomycin concentrations and application methods.
• To determine optimal vancomycin protocols for preventing postoperative infections in ACL reconstruction.

Main Methods:

• Human semitendinosus tendons were inoculated with Staphylococcus aureus, Staphylococcus epidermidis (biofilm and non-biofilm), and Enterococcus faecalis.
• Treatment involved 5-minute direct soaking in 5 mg/mL vancomycin or gauze wrapping with 2.5, 5, or 10 mg/mL vancomycin.
• Bacterial elimination, cell viability (tenocytes, mesenchymal stem cells), and vancomycin release were quantified.

Main Results:

• Complete bacterial eradication was achieved with direct 5 mg/mL soaking and 10 mg/mL gauze wrapping.
• All tested vancomycin concentrations maintained cell viability above 70%, showing no significant cytotoxicity.
• Vancomycin release was highest with direct soaking but remained below chondrocyte toxicity thresholds.

Conclusions:

• A 5-minute direct vancomycin soak (5 mg/mL) or gauze wrap (10 mg/mL) effectively eliminates bacterial contamination on ACL autografts.
• These shortened protocols are safe, preserving tenocyte and mesenchymal stem cell viability.
• This research offers a practical, effective alternative for reducing infection risk in ACL reconstruction.