title: Prevention of venous thromboembolic events with low-molecular-weight heparin in the non-major orthopaedic setting: meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  To assess the efficacy of low-molecular-weight heparin (LMWH) venous thromboprophylaxis in patients with transient reduced mobility in the non-major orthopaedic setting.
  
  
  METHODS
  A meta-analysis was conducted using data from all available randomized trials comparing LMWH with placebo or no prophylactic treatment in patients with leg immobilization for fracture or soft-tissue injury of the lower limb or in patients undergoing knee arthroscopy. The primary endpoint was the incidence of major venous thromboembolic events (VTEs), including asymptomatic proximal deep-vein thrombosis, symptomatic VTEs, and VTE-related death. The Mantel-Haenszel method was used to generate the summary statistics for the overall effect of LMWH.
  
  
  RESULTS
  Fourteen studies were included (4,726 patients). The weighted rate of major VTEs was estimated to be 2.9% (95% confidence interval [CI], 2.2% to 3.7%) without LMWH prophylaxis. Overall, a significant 68% reduction in the risk of major VTEs was observed with LMWH prophylaxis (relative risk [RR], 0.32; 95% CI, 0.20 to 0.51; P < .001). The treatment effect was not modified by the clinical setting, that is, distal lower limb injury (7 studies; 1,711 patients; RR, 0.42; 95% CI, 0.20 to 0.86) or knee arthroscopy (6 studies; 2,428 patients; RR, 0.27; 95% CI, 0.15 to 0.49). A nonsignificant 35% increase in the risk of major bleeding was observed in the LMWH prophylaxis group (RR, 1.35; 95% CI, 0.53 to 3.47).
  
  
  CONCLUSIONS
  This meta-analysis indicates potential efficacy of LMWH in preventing thromboembolic events in patients with reduced mobility in the non-major orthopaedic setting compared with placebo or no treatment. However, the decision of whether to implement LMWH prophylaxis in each specific setting should also take into account the risk of VTEs in the absence of prophylaxis, the potential adverse effects of LMWH, and the cost.
  
  
  METHODS
  Level II, meta-analysis of Level II studies or Level I studies with inconsistent results.
authors.affiliation: INSERM, CIC1408, CHU Saint-Etienne, Saint-Etienne, France. Electronic address: celine.chapelle@chu-st-etienne.fr.
authors.forename: Céline
authors.initials: C
authors.lastname: Chapelle
authors.affiliation: Hôpital de Cochin (AP-HP), Anesthésie-Réanimation, Université Paris Descartes, F-75014, Paris, France.
authors.forename: Nadia
authors.initials: N
authors.lastname: Rosencher
authors.affiliation: Département d'Anesthésie-Réanimation, CHU Saint-Etienne, Saint-Etienne, France; EA3065, Université Jean-Monnet, F-42023, Saint-Etienne, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Jacques Zufferey
authors.affiliation: INSERM, CIC1408, CHU Saint-Etienne, Saint-Etienne, France; Unité de Recherche Clinique Innovation et Pharmacologie, CHU Saint-Etienne, F-42055, Saint-Etienne, France; EA3065, Université Jean-Monnet, F-42023, Saint-Etienne, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mismetti
authors.affiliation: Département de Pharmacologie Clinique, Université de Lyon, F-69376, Lyon, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Cucherat
authors.affiliation: INSERM, CIC1408, CHU Saint-Etienne, Saint-Etienne, France; Unité de Recherche Clinique Innovation et Pharmacologie, CHU Saint-Etienne, F-42055, Saint-Etienne, France; EA3065, Université Jean-Monnet, F-42023, Saint-Etienne, France.
authors.forename: Silvy
authors.initials: S
authors.lastname: Laporte
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001182:Arthroscopy / Q000009:adverse effects*; D050723:Fractures, Bone / Q000150:complications; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D007103:Immobilization / Q000009:adverse effects; D007719:Knee Joint / Q000601:surgery; D007869:Leg Injuries / Q000150:complications*; D035002:Lower Extremity / Q000293:injuries; D016032:Randomized Controlled Trials as Topic; D017695:Soft Tissue Injuries / Q000150:complications; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight