The use of vancomycin and tobramycin in acrylic bone cement - Biomechanical effects and elution kinetics for use in joint arthroplasty

We examined the effects of vancomycin on the compressive strength and fatig ue life of bone cement and the pharmacokinetics and antimicrobial activity against methicillin-resistant Staphylococcus aureus of vancomycin eluted fr om bone cement, both alone and in combination with tobramycin. Two cements, Palaces and Simplex, were tested. Three antibiotic preparations were teste d: lyophilized vancomycin (vancomycin-L), vancomycin powder (vancomycin-P), and tobramycin powder (Lilly, Indianapolis, IN). Although antibiotics did not significantly affect compressive strength, the fatigue life of bone cem ent was significantly decreased with vancomycin. Thus, fatigue testing reve aled effects on cement strength not apparent by compression testing. Vancom ycin-P had a substantially less detrimental effect on fatigue strength than vancomycin-l. Vancomycin-P elutes less efficiently than tobramycin. Althou gh relatively little vancomycin-P eluted from bone cement, it retained biol ogic activity.