Cephalothin and cefamandole penetration into bone, synovial fluid, and wound drainage fluid.

UNLABELLED: Concentrations of cephalothin or cefamandole were measured in serum, bone, synovial fluid, and wound drainage fluid in fifty-seven patients undergoing total hip or knee replacement after a two-gram intravenous bolus injection. The concentrations were similar in serum and synovial fluid for both antibiotics; however, in bone and drainage fluid the concentration of cefamandole was higher by a factor of three. Concentrations of the same antibiotic at the hip and knee were not significantly different even though a tourniquet was used for the knee replacement procedures. CLINICAL RELEVANCE: The antibiotics penetrate bone and enter synovial fluid so rapidly that it is unnecessary to administer prophylactic antibiotics prior to the time of surgery.