title: Comparison of tibiofemoral joint space width measurements from standing CT and fixed flexion radiography.
abstract: The objective of this project was to determine the relationship between medial tibiofemoral joint space width measured on fixed-flexion radiographs and the three-dimensional joint space width distribution on low-dose, standing CT (SCT) imaging. At the 84-month visit of the Multicenter Osteoarthritis Study, 20 participants were recruited. A commercial SCT scanner for the foot and ankle was modified to image knees while standing. Medial tibiofemoral joint space width was assessed on radiographs at fixed locations from 15% to 30% of compartment width using validated software and on SCT by mapping the distances between three-dimensional subchondral bone surfaces. Individual joint space width values from radiographs were compared with three-dimensional joint space width values from corresponding sagittal plane locations using paired t-tests and correlation coefficients. For the four medial-most tibiofemoral locations, radiographic joint space width values exceeded the minimal joint space width on SCT by a mean of 2.0 mm and were approximately equal to the 61st percentile value of the joint space width distribution at each respective sagittal-plane location. Correlation coefficients at these locations were 0.91-0.97 and the offsets between joint space width values from radiographs and SCT measurements were consistent. There were greater offsets and variability in the offsets between modalities closer to the tibial spine. Joint space width measurements on fixed-flexion radiographs are highly correlated with three-dimensional joint space width from SCT. In addition to avoiding bony overlap obscuring the joint, a limitation of radiographs, the current study supports a role for SCT in the evaluation of tibiofemoral OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1388-1395, 2017.
authors: Department of Rehabilitation, The University of Kansas, 3901 Rainbow Boulevard, Mailstop 1046, Kansas City, Kansas, 66160.|Department of Epidemiology, The University of Iowa College of Public Health, Iowa City, Iowa.
authors: Neil A
authors: NA
authors: Segal
authors: Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, Iowa.
authors: Eric
authors: E
authors: Frick
authors: Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts.
authors: Jeffrey
authors: J
authors: Duryea
authors: Department of Epidemiology and Biostatistics, University of California, San Francisco, California.
authors: Michael C
authors: MC
authors: Nevitt
authors: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, Massachusetts.
authors: Jingbo
authors: J
authors: Niu
authors: Department of Epidemiology, The University of Iowa College of Public Health, Iowa City, Iowa.
authors: James C
authors: JC
authors: Torner
authors: Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, Massachusetts.
authors: David T
authors: DT
authors: Felson
authors: Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, Iowa.
authors: Donald D
authors: DD
authors: Anderson
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011187:Posture; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: cartilage loss; imaging; joint space width; knee; osteoarthritis