title: Measuring flexion in knee arthroplasty patients.
abstract: Flexion following total knee arthroplasty can be visually estimated, measured with a goniometer placed against the patient's leg, or measured from a lateral radiograph of the flexed knee. Three examiners, in a blinded fashion, estimated the degree of maximal knee flexion and measured the flexion with a goniometer for 27 knees in 16 patients. A lateral knee radiograph then was taken and the flexion angle was measured from the radiograph by 2 different methods. Although interobserver and intraobserver correlation coefficients were high (0.79 and 0.92), 45% of the visual estimates and 22% of the goniometer measurements differed by 5 degrees or greater from the radiographic measurements. These differences increased as the flexion angle increased. Body mass index did not affect the accuracy of the estimates or goniometer measurements.
authors.affiliation: Walter A. Hoyt, Jr. Musculoskeletal Research Laboratory, Department of Orthopaedic Surgery, Summa Health System, Akron, Ohio, USA.
authors.forename: John Z
authors.initials: JZ
authors.lastname: Edwards
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Greene
authors.forename: Robert S
authors.initials: RS
authors.lastname: Davis
authors.forename: Mark W
authors.initials: MW
authors.lastname: Kovacik
authors.forename: Donald A
authors.initials: DA
authors.lastname: Noe
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Askew
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007720:Knee Prosthesis; D008297:Male; D011859:Radiography; D013977:Tibia / Q000000981:diagnostic imaging