title: Prolonged thromboprophylaxis with Dalteparin during immobilization after ankle fracture surgery: a randomized placebo-controlled, double-blind study.
abstract: BACKGROUND
  Skeletal trauma and immobilization are well-known risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE). While prophylaxis against thromboembolic complications has become routine after major orthopedic surgery, whether or not prophylaxis after minor surgery and lower limb immobilization is necessary is still under debate.
  
  
  METHODS
  In a double-blind, placebo-controlled study, 272 consecutive patients were randomized to receive either thromboprophylaxis with Dalteparin (n = 136) or placebo (n = 136) for 5 weeks after ankle fracture surgery. All patients received 1 week of initial treatment with Dalteparin before randomization. A unilateral phlebography was performed when the cast was removed.
  
  
  RESULTS
  The overall incidence of DVT was 21% (95% CI: 13-29%) in the Dalteparin group and 28% (CI: 19- 37%) in the placebo group (risk ratio = 0.8, CI: 0.6-1.1; p = 0.3). The incidence of proximal DVTs was 4% and 3%, respectively. No major bleeding occurred.
  
  
  CONCLUSIONS
  We found no significant difference in the incidence of DVT between the 2 treatment groups and our results do not support prolonged thromboprophylaxis. The overall incidence of DVT was high, reflecting the potential risk of PE and post-thrombotic syndrome after ankle fracture surgery. Most of the DVTs were asymptomatic, however, and were located in distal veins.
authors.affiliation: Department of Clinical Science and Education, Karolinska Institutet, Stockholm Söder Hospital, Stockholm, Sweden. lasse.lapidus@sodersjukhuset.se
authors.forename: Lasse J
authors.initials: LJ
authors.lastname: Lapidus
authors.forename: Sari
authors.initials: S
authors.lastname: Ponzer
authors.forename: Anders
authors.initials: A
authors.lastname: Elvin
authors.forename: Catharina
authors.initials: C
authors.lastname: Levander
authors.forename: Gerd
authors.initials: G
authors.lastname: Lärfars
authors.forename: Stefan
authors.initials: S
authors.lastname: Rosfors
authors.forename: Edin
authors.initials: E
authors.lastname: de Bri
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016512:Ankle Injuries / Q000601:surgery*; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D002370:Casts, Surgical; D017985:Dalteparin / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D005592:Fracture Fixation / Q000009:adverse effects / Q000379:methods; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D009989:Orthotic Devices; D011183:Postoperative Complications / Q000175:diagnosis / Q000517:prevention & control; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D020246:Venous Thrombosis / Q000175:diagnosis / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D017985:Dalteparin