An internal tourniquet and method for establishing hemostasis within a portion of a limb to facilitate surgery controls flow of a fluid into a capsule surrounding substantially all of a human joint. Blood concentration in the capsule is sensed； and pressure in the capsule is controlled to maintain a fluid pressure in the capsule within a predetermined pressure tolerance window. The concentration of blood in the capsule is maintained below a predetermined maximum concentration while the fluid pressure is within the pressure tolerance window.
