Addition of hand-blended generic tobramycin in bone cement: effect on mechanical strength.

This study compared the mechanical strength of commercially prepared antibiotic bone cement (Simplex With Tobramycin; Stryker, Mahwah, NJ), cement with generic tobramycin (Pharma-Tek, Huntington, NY) blended in by the orthopedic nursing staff, and standard nonantibiotic bone cement. The results showed an approximate 36% decrease in the strength of the cement with hand-mixed generic tobramycin, while the commercial antibiotic cement remained unchanged relative to the nonantibiotic control. These results indicate the mechanical properties of bone cement can be severely compromised by hand-mixing antibiotics into bone cement at the time of surgery.