title: Reliability and validity of carpal alignment measurements in evaluating deformities of scaphoid fractures.
abstract: OBJECTIVE
  Several radiographic carpal alignment indices are used to evaluate the deformities of scaphoid fractures. The purpose of this study was to determine the reliabilities and validities of radiographic carpal alignment indices commonly used to evaluate deformities of scaphoid fractures.
  
  
  METHODS
  Thirty-six patients with a scaphoid fracture were evaluated. Five carpal alignment indices were assessed on lateral plain radiographs, namely, scapholunate angle, radioscaphoid angle, radiolunate angle, radiocapitate angle, and capitolunate angle. Three examiners measured these radiographic indices at two sessions, and intraobserver and interobserver reliabilities were determined and expressed as intraclass correlation coefficients. Discriminant validities of radiographic carpal alignment indicies between injured and uninjured wrists were evaluated. For convergent validity testing, the correlation between the radiographic carpal alignment indices and intrascaphoid angles (ISAs) or height-to-length (HL) ratios on CT longitudinal scans was assessed. Further, carpal alignment indices after surgical reconstruction were compared to the Mayo wrist score.
  
  
  RESULTS
  Scapholunate and radiolunate angles had the highest reliabilities, and radiocapitate angle had the lowest. Radiolunate angle had the highest discriminant validity followed by scapholunate, and capitolunate angles. In convergent validity testing, scapholunate angles and radiolunate angles correlated with ISA angles, and radiolunate and capitolunate angles correlated with HL ratios. Only the radiolunate angles correlated with the Mayo wrist scores.
  
  
  CONCLUSIONS
  Among radiographic carpal alignment measures, radiolunate angle is the most reliable and valid carpal alignment index for evaluating deformities of scaphoid fractures. Scapholunate and capitolunate angles could be used as an alternative, but have less validity.
authors.affiliation: Department of Orthopaedic Surgery, Gil Medical Center, Gachon University School of Medicine, Inchon, Korea.
authors.forename: Young Hak
authors.initials: YH
authors.lastname: Roh
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Noh
authors.forename: Beom Koo
authors.initials: BK
authors.lastname: Lee
authors.forename: Jong Ryoon
authors.initials: JR
authors.lastname: Baek
authors.forename: Joo Han
authors.initials: JH
authors.lastname: Oh
authors.forename: Hyun Sik
authors.initials: HS
authors.lastname: Gong
authors.forename: Goo Hyun
authors.initials: GH
authors.lastname: Baek
mesh_terms: D000328:Adult; D002348:Carpal Bones / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D019651:Plastic Surgery Procedures / Q000379:methods*; D015203:Reproducibility of Results; D021361:Scaphoid Bone / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014954:Wrist Injuries / Q000000981:diagnostic imaging / Q000601:surgery*