Tourniquet inflation during total knee arthroplasty (TKA) is commonly used to reduce bleeding in the surgical field; thereby facilitating exposure and cementation. However, reducing circulation to the leg may also reduce antibiotic distribution to the peri-incisional tissues. Once inflated, further parenteral addition of antibiotics is not likely to achieve peak concentration. Some studies propose techniques of regional prophylaxis with a tourniquet to achieve higher cefazolin tissue concentrations. To our knowledge, the effect of tourniquet application on antibiotic tissue concentrations during total knee arthroplasty has not been explored. Furthermore, the effect of time from dose to incision, participants weight, and length of surgery on local tissue concentrations of Ancef are poorly understood. Considering that infections remain the leading source of early reoperation and revision surgery, insight and optimization of local tissue antibiotics is of paramount interest.