Measuring flexion in knee arthroplasty patients.
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.
Edwards
John Z
JZ
Walter A. Hoyt, Jr. Musculoskeletal Research Laboratory, Department of Orthopaedic Surgery, Summa Health System, Akron, Ohio, USA.
Greene
Kenneth A
KA
Davis
Robert S
RS
Kovacik
Mark W
MW
Noe
Donald A
DA
Askew
Michael J
MJ
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