The efficacy comparison on femoral vein hemodynamics and morphology between two types of graduated elastic compression stockings among patients undergoing knee replacement: a single center, double-blind, randomized trial

Abstract

Background. Venous thromboembolism is a significant complication after knee replacement. The short-term efficacy disparities between different types of graduated elastic compression stockings (GCS) among patients undergoing total/unicompartmental knee replacement remain unclear. Objective. The aim of the trial was to compare the efficacies on hemodynamics and morphology of femoral vein between two types of GCS, providing more evidence on GCS prophylaxis among patients undergoing total/unicompartmental knee replacement. Methods. In this single center, double-blind, parallel design, randomized trial, 141 adult patients who underwent selective, unilateral total/unicompartmental knee replacement operation for the first time were enrolled, with 71 were assigned to type A GCS and 70 to type B GCS, respectively. Compressed ultrasound of the lower extremity was conducted before the operation (without GCS, as preoperative baseline) and within 24 hours post operation (postoperative baseline, with GCS, and with GCS + ankle pump). The relative changes in TV and PV, as well as the diameter of the femoral vein in the healthy leg, were assessed both before and after GCS application following the knee replacement surgery. Results. The median ages were 67.0 years in type A group and 68.0 years in type B group. All parameters of femoral vein were comparable between type A and type B GCSs. Compared with postoperative baseline, GCS + ankle pump significantly reduced femoral vein diameter and improved the TV in both GCS types; GCS and GCS + ankle pump also significantly increased the TV (median 1.2%, IQR −21.4% to 58.6%, P = 0.0384; median 14.0%, IQR −24.3% to 93.0%, P = 0.0019, respectively) in left leg, while not significant in right leg. Conclusion. The efficacies of two GCSs were comparable, and both were effective in improving velocity and morphology of femoral veins of the healthy legs among patients undergoing knee replacement, especially in improving TVs of femoral veins for left leg.