VENOUS HEMODYNAMICS IN BOTH LEGS AFTER TOTAL KNEE REPLACEMENT

We studied the effect of total knee replacement on venous flow in 110 patients. Resting venous blood flow was measured using strain-gauge pl ethysmography before operation, after surgery and after discharge from hospital, There was a significant reduction in mean venous capacitanc e (p < 0.001) and mean venous outflow (p < 0.004) affecting only the o perated leg. Both improved significantly after mobilisation in the ear ly postoperative period, returning to preoperative levels by six days after surgery and before discharge from hospital. Our findings showed that venous stasis may contribute to deep-vein thrombosis only in the first few days after total knee replacement, This would be the most im portant period for the use of flow-enhancing prophylactic devices. Com parison with changes in blood flow after total hip replacement identif ied different patterns of altered haemodynamics suggesting that there are different mechanisms of venous stasis and thrombogenesis in hip an d knee arthritis and during surgery for these conditions.