Westrich GH, Sculco TP.
Prophylaxis against deep venous thrombosis after total arthroplasty. Pneumatic
plantar compression and aspirin compared with aspirin alone.
J Bone Joint Surg Am 1996 Jun;78(6):826-34

Hospital for Special Surgery, New York, N.Y. 10021, USA.

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.