title: The incidence of pulmonary embolism and deep vein thrombosis after knee arthroplasty in Asians remains low: a meta-analysis.
abstract: BACKGROUND
  While Western literature has mostly reported the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) after TKA with chemoprophylaxis, the Asian literature still has mostly reported the incidence without chemoprophylaxis. This may reflect a low incidence of DVT and PE in Asian patients, although some recent studies suggest the incidence after TKA in Asian patients is increasing. Moreover, it is unclear whether the incidence of DVT and PE after TKA is similarly low among different Asian countries.
  
  
  OBJECTIVE
  We therefore determined the overall incidence of symptomatic PE and DVT without chemoprophylaxis after TKA in the Asian population, determined whether the incidence had a tendency to increase over time in Asia, and compared the incidence of symptomatic PE and DVT among Asian countries through a meta-analysis.
  
  
  METHODS
  We searched the PubMed, Embase, Cochrane Library, Web of Science, and Google Scholar websites for prospective studies published between 1996 and 2011. A total of 1947 patients from 18 studies were reviewed for meta-analysis.
  
  
  RESULTS
  The incidence of symptomatic PE was 0.01%. The incidences of overall DVT, proximal DVT, and symptomatic DVT were 40.4%, 5.8% and 1.9%, respectively. We found no difference in incidence of symptomatic PE among Asian countries and no trends in changes of the incidence over time.
  
  
  CONCLUSIONS
  The incidence of symptomatic PE and DVT after TKA without prophylaxis is low in Asian countries and has not changed over time, despite Westernizing lifestyles and an aging populace. Further investigation with large randomized studies is necessary to confirm our findings and identify risk factors predisposing to DVT.
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University Gangnam Severance Hospital, Seoul, Korea.
authors.forename: Woo-Suk
authors.initials: WS
authors.lastname: Lee
authors.forename: Kang-Il
authors.initials: KI
authors.lastname: Kim
authors.forename: Han-Jun
authors.initials: HJ
authors.lastname: Lee
authors.forename: Hee-Soo
authors.initials: HS
authors.lastname: Kyung
authors.forename: Seung-Suk
authors.initials: SS
authors.lastname: Seo
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001208:Asia / Q000453:epidemiology; D044466:Asian People; D006801:Humans; D011655:Pulmonary Embolism / Q000208:ethnology*; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D020246:Venous Thrombosis / Q000208:ethnology*