[Serum, knee synovial fluid and joint tissue cefuroxime concentration in perioperative use before orthopedic interventions after tourniquet or in the bloodless field].

A requirement to be met when administering perioperative prophylactic antibiotics as a standard with many orthopedic surgeons in artificial joint replacement is the achievement of sufficient concentrations of substance in the operative field. Following the i.v. short-infusion of 1.5 mg Cefuroxime-Sodium in 65 cases of knee joint surgery using a mid-thigh tourniquet substance levels were measured in samples of blood serum, synovial fluid and knee joint capsule. The Cefuroxime concentration in synovial fluids was found to be an average of 25.3 +/- 15.4 mcg/ml at the beginning and 14.9 +/- 10.7 mcg/ml at the end of the operations. Samples of joint capsule that had been taken during the operation showed substance levels of 20.6 +/- 11.1 mcg/ml. 13% of these samples showed substance levels below 4.0 mcg/ml which is the estimated breakpoint of full sensitivity of potentially infective bacteria. The relation of Cefuroxime concentrations in the synovial fluid to the length of time between the end of the infusion and the application of the tourniquet proved to be statistically nonsignificant (covariance analysis; p = 0.05). Nevertheless the determined differences showed a tendency which agrees with the findings of other authors who conclude, that a minimum exposure time of ten minutes is essential.