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

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.

The antibiotics penetrate bone and enter synovial fluid so rapidly that it is unnecessary to administer prophylactic antibiotics prior to the time of surgery.