Impact Resistance of Antibiotic-Impregnated Orthopedic Bone Cement

Abstract

The usess of antibiotic--impregnated bone cement in total joint replacement (TJR) is a common practice but remains extremely variable. The benefit of adding antibiotics to bone cement as a method of infection prophylaxis in TJR needs to be weighed against a number of drawbacks primarily a drop in the mechanical properties of the bone cement. The present study utilized the pendulum impact strength testing to report on the properties of antibiotic-impregnated cement. All testing was conducted in accordance with ASTM D256-06. Test groups included: PMMA mixed with vancomycin, gentamicin, erythromycin or no antibiotic (control). Also, the effect of aging samples in air versus saline on the impact strength was studied. The effect of antibiotic addition to cement on the impact strength was found statistically significant (p < 0.05). The Tukey's HSD test indicated that the liquid Gentamicin impregnated samples aged in air had significantly lower mean impact strength than all other groups (p < 0.05). The mean impact strength of the vancomycin added samples aged in saline was lower than other samples aged in saline but is not statistically significant (p > 0.05).