title: Comparison between Staheli index on Harris mat footprint and Talar-first metatarsal angle for the diagnosis of flatfeet.
abstract: BACKGROUND
  Flatfoot is practically diagnosed by physical examination, radiographs, or footprint. Talar first-metatarsal angle on a weight-bearing lateral radiograph provides an accurate measurement for the diagnosis offlatfoot and is frequently used by foot and ankle specialists. Staheli Index is also considered as a reliable method. However; there is no information of the sensitivity and specificity of this index compared to the talar-first metatarsal angle for the diagnosis of flatfoot.
  
  
  OBJECTIVE
  To evaluate the usefulness of the Staheli Index on Harris matfootprintfor the diagnosis of flatfoot.
  
  
  METHODS
  The weight-bearing lateral radiographs were obtainedfrom 157patients (314feet). The radiographs were examined for the talar-first metatarsal angle. Harris mat footprint was also obtained from each participant for the measurement of the Staheli Index. The sensitivity and specificity of the Staheli Index was calculated using the talar-first metatarsal angle as a gold standard. ROC curve was also performed to determine the cut-off point of the Staheli Index. Interobserver and intra-observer reliability was also tested.
  
  
  RESULTS
  The cut-off point ofthe Staheli Index at 0.77 revealed the sensitivity of 70.2% and specificity of 73%, and the accuracy value was 72%for the detection of flatfoot compare4 to the talar-first metatarsal angle. There was no significant difference of the area under the ROC curves performed by two physicians was found. The area under the ROC curves showed no difference when performed at two different times by the same physician.
  
  
  CONCLUSIONS
  The Staheli Index obtained from the Harris mat footprint could be considered as the screening or diagnostic method for flatfoot.
authors.forename: Yanin
authors.initials: Y
authors.lastname: Plumarom
authors.forename: Worarachanee
authors.initials: W
authors.lastname: Imjaijitt
authors.forename: Nusorn
authors.initials: N
authors.lastname: Chaiphrom
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005413:Flatfoot / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008682:Metatarsal Bones / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010808:Physical Examination; D012372:ROC Curve; D011859:Radiography; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016474:Weight-Bearing