Vancomycin vs tobramycin elution from polymethylmethacrylate: an in vitro study

We fabricated batches of cement containing 0.5 gm, 1.0 gm, and 2.0 gm vancomycin and one with 1.0 gm tobramycin and shaped them into cylinders. They were immersed into 0.5 L of normal saline and the fluid volume was changed daily. Samples of fluid were obtained on days 1, 2, 3, 5, 7, 14, and 28. All fluid samples had antibiotic assays performed to quantitate the amount of elution for vancomycin or tobramycin. Vancomycin elution from PMMA occurred under our study conditions in similar quantities to that measured for tobramycin controls. Vancomycin-loaded PMMA cement may have a clinical role in the treatment of musculoskeletal sepsis caused by gram-positive bacteria, particularly if organisms resistant to the usual antibiotic agents are identified.