58 The Journal of Rheumatology 2013; 40:1; doi:10.3899/jrheum.120320 Personal non-commercial use only. The Journal of Rheumatology Copyright © 2013. All rights reserved. Quantitative Radiographic Features of Early Knee Osteoarthritis: Development Over 5 Years and Relationship with Symptoms in the CHECK Cohort MARGOT B. KINDS, ANNE C.A. MARIJNISSEN, JOHANNES W.J. BIJLSMA, MAARTEN BOERS, FLORIS P.J.G. LAFEBER, and PACO M.J. WELSING ABSTRACT. Objective. To evaluate whether computer-assisted, interactive digital analysis of knee radiographs enables identification of different quantitative features of joint damage, and to evaluate the relationship of such features with each other and with clinical characteristics during 5-year followup in early osteoarthritis (OA). Methods. Knee radiographs from the Cohort Hip and Cohort Knee (CHECK) study, including 1002 individuals with early OA complaints, were evaluated for different measures with knee images digital analysis (KIDA). To aid definition of different radiographic features of OA, principal component analysis of KIDA was used. Features were correlated (Pearson) to each other, evaluated for changes over time, and related to clinical outcome (Western Ontario and McMaster Universities Osteoarthritis Index for pain and function) using baseline, 2-year, and 5-year followup data. Results. The identified radiographic features were joint space width (JSW: minimum, medial, lateral), varus angle, osteophyte area, eminence height, and bone density. The features progressed in severity at different times during followup: early (medial JSW, osteophyte area), late (minimum and lateral JSW, eminence height), and both early and late (varus angle, bone density). Correlations between different radiographic features varied between timepoints. The JSW features were most strongly related to each other (largest r = 0.82), but also, e.g., osteophytes and bone density were correlated (largest r = 0.33). The relationships with clinical outcome varied over time, but were most commonly found for osteophyte area and JSW. Conclusion. In this early OA cohort, different radiographic features were identified that progressed at different rates between timepoints. The relations between radiographic features and with clinical outcome varied over time. This implies that longitudinal evaluation of different features can improve insight into progression of OA. (First Release Nov 1 2012; J Rheumatol 2013;40:58–65; doi:10.3899/jrheum.120320) Key Indexing Terms: KNEE JOINT OSTEOARTHRITIS RADIOGRAPHY From Rheumatology and Clinical Immunology, the Image Sciences Institute, and the Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht; and Epidemiology and Biostatistics, VU University Medical Center Amsterdam, Amsterdam, The Netherlands. The CHECK study is supported by the Dutch Arthritis Association. M.B. Kinds, PhD, Rheumatology and Clinical Immunology, Image Sciences Institute, University Medical Center Utrecht; A.C.A. Marijnissen, PhD; J.W.J. Bijlsma, MD, PhD, Professor, Rheumatology and Clinical Immunology, University Medical Center Utrecht; M. Boers, MD, PhD, Professor, Epidemiology and Biostatistics, VU University Medical Center Amsterdam; F.P.J.G. Lafeber, PhD, Professor, Rheumatology and Clinical Immunology, University Medical Center Utrecht; P.M.J. Welsing, PhD, Rheumatology and Clinical Immunology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht. Address correspondence to Dr. P.M.J. Welsing, Rheumatology and Clinical Immunology, University Medical Center Utrecht, F02.127, PO Box 85500, 3508 GA Utrecht, The Netherlands. E-mail: P.M.J.Welsing@umcutrecht.nl Accepted for publication September 14, 2012. Osteoarthritis (OA) is the most common joint disorder 1 , characterized by pain, functional disability, and limited quality of life. Structural changes affect the whole joint and comprise cartilage damage, osteophyte formation, changes in subchondral bone density, synovial inflammation, and involvement of soft tissue (such as ligaments and muscles) 2 . Diagnosis of OA, especially in an early phase of the disease, is difficult because of the lack of sensitive and specific diagnostic criteria 3,4 . The inconsistent association that is commonly found between clinical symptoms and radio- graphic characteristics representing structural damage hampers definition of such criteria 5,6,7 . The detection of an association might be improved by measuring different features of radiographic OA. Evaluation of different features over time, from a very early phase of the disease, might provide more insight into the development and progression of structural damage. For example, the detailed evaluation of such features might reveal a sequence in the development of specific radiographic aspects during the course of the disease, and the existence of specific relationships between aspects of radiographic damage over time. www.jrheum.org Downloaded on December 10, 2021 from