title: Safety and efficiency of the Ottawa Ankle Rule in a Swiss population with ankle sprains.
abstract: We examined the accuracy of the Ottawa Ankle Rule (OAR) to rule out ankle and mid-foot fractures in patients presenting with acute ankle sprain and differences of accuracy between surgeons and non-surgeons.
  
  
  
  Prospective cohort study.
  
  
  
  Swiss urban secondary care centre.
  
  
  
  Between September 2001 and October 2002 359 patients presented with a case of ankle sprain. Of these, 251 patients both met recruitment criteria and provided data for this study. A group of surgeons and non-surgeons assessed the OAR and all patients underwent blinded radiographic assessment.
  
  
  
  Sensitivity, specificity of the OAR.
  
  
  
  Of the 251 patients with ankle sprains 33 had an ankle fracture (13%) and none had a mid-foot fracture. All cases with a fracture had a positive OAR result (sensitivity 100% 95% CI; 89-100) and of 218 patients without a fracture, the OAR was negative in 45 cases (specificity 21%; 16-27). In the subgroup of patients assessed by surgeons, sensitivity was 100% (77-100) and specificity was 32% (20-46). In the non-surgical group, sensitivity was also 100% (82-100) but specificity was lower (17% (11-23).
  
  
  
  This validation study of the OAR in a Swiss setting produced similar results than those published previously in various other settings. We found differences in the performance of the rule between surgical and non-surgical staff indicating that the OAR has its interpretation component which is more difficult to judge properly by well-instructed non-surgical assessors.
authors.affiliation: Surgical Clinic, Stadtspital Triemli, Zürich, Switzerland.
authors.forename: Unal
authors.initials: U
authors.lastname: Can
authors.forename: Rolf
authors.initials: R
authors.lastname: Ruckert
authors.forename: Ulrike
authors.initials: U
authors.lastname: Held
authors.forename: Peter
authors.initials: P
authors.lastname: Buchmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Platz
authors.forename: Lucas M
authors.initials: LM
authors.lastname: Bachmann
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D016512:Ankle Injuries / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D005260:Female; D018409:Foot Injuries / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011859:Radiography; D012680:Sensitivity and Specificity; D013180:Sprains and Strains / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D013557:Switzerland