Antibiotic prophylaxis is a brief course of antibiotics initiated preoperatively in order to decrease the risk of postoperative wound infection. Prophylactic antibiotics are not a substitute for proper aseptic technique; rather, they are an additional measure used to decrease infection risk. Optimally, an antibiotic level exceeding the minimum inhibitory concentration of that antibiotic for the infecting organism should be maintained in the tissue from incision through wound closure. Use of prophylaxis implies an absence of established infection and gross contamination of the tissues.