Effect of external sequential compression devices on femoral venous blood flow.

Sequential compression devices are used to reduce venous stasis and deep venous thrombosis after joint replacement. Thigh-length, calf-length, and foot compression devices were compared in using ultrasonography after unilateral knee arthroplasty. Simulated muscle activity via active ankle motion was also evaluated. Blood flow volume and velocity were recorded above and below the saphenous vein bifurcation, the division of the superficial and deep systems, allowing evaluation of each. Volume and velocity increased in the superficial and deep systems with all devices. A control group was evaluated to determine differences related to age and surgery. The devices performed similarly in the volunteers. However, active motion performed better than any device. Thus, unlike young, healthy patients, muscle activity alone in the operative population was unreliable in increasing blood flow. Thigh-length, calf-length, and foot compression devices are are effective at increasing femoral blood flow volume and velocity in the deep and superficial venous systems after total knee arthroplasty.