A prospective, randomized study was conducted to assess the efficacy of pulsatile pneumatic plantar compression for prophylaxis against
deep venous thrombosis after
total knee arthroplasty performed with use of
regional anesthesia. One hundred and twenty-two patients (164 knees) who were scheduled to have a unilateral or a one-stage bilateral
total knee arthroplasty were separately randomized to be managed with either
aspirin alone or the pulsatile pneumatic plantar-compression device and
aspirin. The prevalence of
deep venous thrombosis was 27 per cent (twenty-two of eighty-one knees) in the group treated with pneumatic plantar compression compared with 59 per cent (forty-nine of eighty-three knees) in the patients managed with
aspirin alone (the control group) (p < 0.001). A significant difference was also noted in the group that had had a unilateral
arthroplasty (a prevalence of 27 per cent [eleven of forty-one knees] in the group treated with pneumatic plantar compression, compared with 67 per cent [twenty-six of thirty-nine knees] in that treated with
aspirin alone; p < 0.006) and in the group that had had a one-stage bilateral procedure (a prevalence of 28 per cent [eleven of forty knees] in the group treated with pneumatic plantar compression, compared with 52 per cent [twenty-three of forty-four knees] in that treated with
aspirin alone; p < 0.03). No proximal thrombi were noted in any patient who used the pulsatile pneumatic plantar-compression device, while the prevalence of proximal
thrombosis in the popliteal or femoral veins was 14 per cent (twelve of eighty-three knees) in the group treated with
aspirin alone (p < 0.0003). In the group treated with a unilateral procedure and
aspirin alone the prevalence of proximal
thrombosis was 13 per cent (five of thirty-nine knees; p < 0.02), while in the group treated with a bilateral procedure and
aspirin alone it was 16 per cent (seven of forty-four knees; p < 0.01). Only in the patients who had had a unilateral procedure was use of the compression device associated with significantly less
edema postoperatively than was use of
aspirin alone. The change between the preoperative and postoperative circumferences of the thigh and leg was significantly less (9 +/- 4.1 millimeters [mean and standard deviation] less for the thigh [p < 0.01] and 6 +/- 3.9 millimeters less for the leg [p < 0.049]) with the compression device than with
aspirin alone. In addition, there was significantly less mean drainage (98 +/- 61.1 milliliters) in the group treated with a unilateral procedure and pneumatic compression, compared with that treated with a unilateral procedure and
aspirin alone (p < 0.041). An internal timer of the compression device was used to assess the compliance of the patient with use of the device, and a relationship between
deep venous thrombosis and the total
duration of treatment with the device was found. The patients in whom
deep venous thrombosis did not develop used the device for a mean of 96 +/- 23.4 hours (range, sixty to 164 hours) postoperatively, or 19.2 +/- 5.1 hours a day, while those in whom
thrombosis developed used it for a mean of 67 +/- 21.1 hours (range, twenty-six to 101 hours), or 13.4 +/- 4.3 hours a day (p < 0.001). No untoward effects were noted in any patient who used the device. This study confirms the safety and efficacy of pulsatile pneumatic plantar compression and
aspirin compared with
aspirin alone and supports the use of mechanical compression for prophylaxis against
deep venous thrombosis and for reduction of
edema in patients who have had a
total knee arthroplasty. In addition, we found a direct relationship between compliance with the use of this device and its efficacy in reducing
deep venous thrombosis.