title: Prevention of deep-vein thrombosis in ambulatory arthroscopic knee surgery: A randomized trial of prophylaxis with low--molecular weight heparin.
abstract: OBJECTIVE
  The risk of deep vein thrombosis (DVT) in patients undergoing arthroscopic knee surgery is not well known. The purpose of this study was to determine the incidence of DVT, to demonstrate the efficacy of a perioperative and postoperative prophylaxis against thromboembolism with use of low--molecular weight heparin (LMWH), and to show the safety and feasibility of LMWH administration.
  
  
  METHODS
  Prospective, single-blind, randomized clinical trial.
  
  
  METHODS
  There were 218 consecutive outpatients scheduled for ambulatory arthroscopic knee surgery eligible. Of these, 130 patients were randomized to a treatment group with LMWH (dalteparin: 2,500 IU less-than-or-equal70 kg and 5,000 IU >70 kg, started perioperatively and given once daily for 4 weeks; n = 66) and a control group (n = 64) with no prophylaxis. To detect DVT, all patients underwent bilateral compression ultrasonography before and 12 and 31 days after surgery.
  
  
  RESULTS
  Among the 130 patients studied, thromboembolism was significantly lower in the treatment than in the control group: 1 of 66 (1.5%) versus 10 of 64 (15.6%); 95% confidence interval, 7.8% to 26.8%; P =.004. Eighty percent of DVT occurred within the first 14 postoperative days. No severe side effects of LMWH were observed. Only 5% of patients refused continued subcutaneous LMWH injections.
  
  
  CONCLUSIONS
  In patients undergoing ambulatory arthroscopic knee surgery without antithrombotic prophylaxis, the risk of DVT is high. Perioperative and postoperative prophylaxis with dalteparin is an effective and safe means of reducing this risk.
authors.affiliation: Department of Internal Medicine, General Internal Medicine, Kantonsspital Aarau, Aarau, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Michot
authors.forename: Dieter
authors.initials: D
authors.lastname: Conen
authors.forename: Daniel
authors.initials: D
authors.lastname: Holtz
authors.forename: Daniel
authors.initials: D
authors.lastname: Erni
authors.forename: Marc Daniel
authors.initials: MD
authors.lastname: Zumstein
authors.forename: Georg Bernhard
authors.initials: GB
authors.lastname: Ruflin
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Renner
mesh_terms: D000328:Adult; D000556:Ambulatory Surgical Procedures / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001182:Arthroscopy / Q000009:adverse effects*; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D007717:Knee / Q000601:surgery*; D008297:Male; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight