Department of Chemistry

Bone cement (PMMA) is essential for cemented total joint replacement (TJR), and it is also used in the repair of bony defects and for augmenting fracture fixation for osteoporotic bones.  For several years, we have tested the mechanical properties of normal and antibiotic (Gentamycin and Tobramycin) mixed bone cement. Our results showed that addition of low dose antibiotics did not significantly affect the compressive strength of bone cement.  However, addition of high dose of some antibiotics (10 to 15 % by weight) did reduce the compressive load carrying capacity of bone cement.  We also evaluated the change in compressive properties after elution of antibiotics for various time periods up to ninety days.  Our results showed that high dose of antibiotics added to bone cement negatively affected the compressive properties of bone cement and was more important than the duration of drug elution from the samples.