title: Effect of mechanical compression on the prevalence of proximal deep venous thrombosis as assessed by magnetic resonance venography.
abstract: BACKGROUND
  Patients have been shown to be at greater risk for deep venous thrombosis, particularly proximal thrombosis, after total hip arthroplasty. Proximal thrombi are more likely to develop into pulmonary emboli than are distal thrombi. The purpose of this randomized, prospective study was to compare the prevalence of pelvic and proximal lower-extremity deep venous thrombosis after primary total hip arthroplasty between patients treated with an impulse mechanical compression device for prophylaxis and those treated with prophylactic stockings.
  
  
  METHODS
  One hundred patients were evaluated, with use of magnetic resonance venography, for proximal deep venous thrombosis after total hip arthroplasty. Fifty patients were treated with a mechanical compression device on both lower extremities, and the other fifty patients received only prophylactic stockings. Both groups of patients received hypotensive epidural anesthesia and 325 mg of aspirin twice a day.
  
  
  RESULTS
  Overall, proximal deep venous thrombi were found in 15% of the 100 patients. Of the fifty patients treated with mechanical compression, 8% (four) had a positive venogram. Of the fifty control patients, 22% (eleven) had a positive venogram (p < 0.05). However, overall the rate of occlusive thrombi was 6% (six) compared with an overall rate of nonocclusive thrombi of 9% (nine). The rate of occlusive thrombi was 2% (one of fifty) in the study group and 10% (five of fifty) in the control group (p = 0.04).
  
  
  CONCLUSIONS
  On the basis of this study, we concluded that patients managed with total hip arthroplasty benefit from a reduction in the rates of femoral and pelvic deep vein thrombosis when they are treated with hypotensive epidural anesthesia, mechanical compression, and aspirin and are subsequently assessed with magnetic resonance venography.
authors.affiliation: The Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ryan
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Westrich
authors.forename: Hollis G
authors.initials: HG
authors.lastname: Potter
authors.forename: Nigel
authors.initials: N
authors.lastname: Sharrock
authors.forename: Lena M
authors.initials: LM
authors.lastname: Maun
authors.forename: William
authors.initials: W
authors.lastname: Macaulay
authors.forename: Pamela
authors.initials: P
authors.lastname: Katkin
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Sculco
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Salvati
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D005676:Gravity Suits; D006801:Humans; D018810:Magnetic Resonance Angiography; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D020246:Venous Thrombosis / Q000175:diagnosis / Q000517:prevention & control*