We recruited 89 patients who had hip or knee replacements to assess the performance of below-knee graded compression stockings. The pressure gradients generated by the stockings were measured and all patients had venography of the ipsilateral leg. We found that 98% of stockings failed to produce the ‘ideal’ pressure gradient (± 20%) of 18, 14 and 8 mmHg from the ankle to the knee, while 54% produced a ‘reversed gradient’ on at least one occasion during the course of the study. The overall rate of deep-venous thrombosis was 16.7%. Stockings which produced reversed gradients were associated with a significantly higher incidence of deep-venous thrombosis (p = 0.026) than those with the correct gradient (25.6%
