In vitro comparison between commercially and manually mixed antibiotic-loaded bone cements

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Infectious Disease Prevention

Background:

• Poly-methyl methacrylate (PMMA) bone cements are widely used in prosthetic devices.
• Antibiotic-loaded bone cements are crucial for preventing surgical site infections.
• Manual preparation of antibiotic-loaded bone cement allows for customization but may differ from industrial standards.

Purpose of the Study:

• To compare the antibacterial efficacy of manually prepared gentamicin-loaded bone cements versus a commercial formulation.
• To evaluate the impact of adding vancomycin to gentamicin-loaded bone cements.
• To determine potential advantages or disadvantages of manual versus industrial bone cement preparations.

Main Methods:

• Medical-grade PMMA bone cements (Palacos R®, Palacos LV®) were manually enriched with gentamicin sulfate.
• Manual formulations were compared to a commercial antibiotic-loaded cement (Palacos R+G®).
• In vitro antibacterial activity was assessed using inhibition zone evaluation. Vancomycin was also tested alone and in combination with gentamicin.

Main Results:

• The commercial bone cement formulation exhibited a slightly larger and more regular inhibition zone compared to manual preparations.
• Vancomycin demonstrated a smaller but clearer inhibition zone than gentamicin.
• Co-administration of vancomycin with gentamicin did not significantly enhance the inhibition zone size.

Conclusions:

• Commercial bone cement formulations may offer a more consistent antibacterial effect.
• Vancomycin-loaded bone cement shows potential for treating infections caused by resistant bacteria.
• Combining vancomycin with gentamicin warrants further investigation for preventing complex and resistant orthopedic infections.