title: Effect of wrist position on the measurement of carpal indices on the lateral radiograph.
abstract: The purpose of this study was to find out whether the carpal indices measured on lateral radiographs with a slightly malpositioned wrist are the same as those measured in the true neutral position. Lateral radiographic views of 25 wrists were taken with 5° intervals from 20° of flexion to 20° of extension. Most carpal indices measured in the flexed or extended position were significantly different from the wrist in zero flexion-extension, except scapholunate angle at 5° of extension and scaphocapitate angle at 5° and 10° of flexion. Starting from the flexed position, there was an average of -4.0° change in radioscaphoid angle, -1.0° in scapholunate angle, -1.0° in scaphocapitate angle, +3.0° in radiolunate angle, and +2.0° in lunocapitate angle for each 5° of extension with linear trends. The results from this study suggest that even minimal degrees of flexion-extension can affect the measurements of carpal indices on lateral radiographs.
authors.affiliation: Department of Orthopaedic Surgery, Seoul Medical Center, Seoul, Republic of Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Koh
authors.forename: H I
authors.initials: HI
authors.lastname: Lee
authors.forename: K S
authors.initials: KS
authors.lastname: Lim
authors.forename: J S
authors.initials: JS
authors.lastname: Seo
authors.forename: M J
authors.initials: MJ
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D002348:Carpal Bones / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011859:Radiography; D015203:Reproducibility of Results; D014955:Wrist Joint / Q000000981:diagnostic imaging* / Q000601:surgery