title: Low incidence of symptomatic thromboembolic events after total ankle arthroplasty without routine use of chemoprophylaxis.
abstract: BACKGROUND
  There is little evidence regarding the incidence of symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) to allow formulation of treatment recommendations. The purpose of this study was to determine the incidence of symptomatic VTE events after TAA without use of chemoprophylaxis and to identify risk factors contributing to the occurrence of VTEs.
  
  
  METHODS
  We conducted a retrospective chart review of 637 patients (664 ankles) who received a TAA between May 2007 and January 2014 and had a minimum follow-up of 3 months. Chemoprophylaxis was prescribed only in the setting of a history of VTE or active coagulopathy. Patients were continued on chemoprophylactic agents if they were taking these medications preoperatively. A VTE event was defined when clinical signs and symptoms of deep venous thrombosis (DVT) were confirmed with use of Doppler ultrasonography or pulmonary embolism was confirmed with the use of a computed tomography scan. Routine screening for VTE was not performed.
  
  
  RESULTS
  The overall incidence of clinically detected VTE events was 0.60% (4/664), with 0.45% (3 patients) developing a DVT and 0.15% (1 patient) developing a nonfatal pulmonary embolism. Moreover, we identified a subset of 434 patients without identifiable preoperative risk factors who were not taking chemoprophylaxis preoperatively and were not prescribed chemoprophylaxis postoperatively. Two of these patients developed a DVT postoperatively (0.46%). Given the low incidence of clinically detected VTE, no significant correlation could be identified between the occurrence of VTE events and risk factors.
  
  
  CONCLUSIONS
  Our results suggest that clinically detectable VTE after TAA is uncommon. Patients without identifiable risk factors do not appear to require chemoprophylaxis following TAA. We recommend continuation of antiplatelet or anticoagulation therapy in patients who are taking these medications preoperatively and the initiation of chemoprophylaxis postoperatively in patients with known risk factors for VTE.
  
  
  METHODS
  Level IV, case series.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Phillip H
authors.initials: PH
authors.lastname: Horne
authors.affiliation: Colorado Joint Replacement, Denver, CO, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Jennings
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: DeOrio
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Easley
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Nunley
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA samuel.adams@duke.edu.
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Adams
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058737:Arthroplasty, Replacement, Ankle / Q000009:adverse effects*; D018890:Chemoprevention; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000209:etiology*; D055815:Young Adult
keywords: ankle arthroplasty; ankle replacement; chemoprophylaxis; deep vein thrombosis; venous thromboembolism