Jan 22, 2010 - radiographic osteoarthritis detected by directional fractal signature method. M. Wolski y*, P. .... Radiographs were digitized to 256 bit grey scale.
Osteoarthritis and Cartilage 18 (2010) 684e690
Differences in trabecular bone texture between knees with and without radiographic osteoarthritis detected by directional fractal signature method M. Wolski y *, P. Podsiadlo y, G.W. Stachowiak y, L.S. Lohmander z, M. Englund zx y Tribology Laboratory, School of Mechanical Engineering, University of Western Australia, Australia z Musculoskeletal Sciences, Department of Orthopedics, Clinical Sciences Lund, Lund University, Sweden x Clinical Epidemiology Research & Training Unit, Boston University School of Medicine, Boston, MA, USA
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Article history: Received 10 June 2009 Accepted 22 January 2010
Objective: To evaluate differences in tibial trabecular bone (TB) texture between subjects with and without radiographic knee osteoarthritis (OA) using a variance orientation transform (VOT) method. Design: Subjects with knee OA (Kellgren & Lawrence grade 2) and controls without OA (both n ¼ 26, seven women) were matched by sex, age, body mass index and compartment. The VOT method was applied to TB X-ray images and fractal signature and dimension in horizontal (FSH, FDH) and vertical (FSV, FDV) directions and along the roughest part of TB (FSSta, FDSta), texture aspect ratio (Str) and signature (StrS), and mean FD (FDMEAN) were calculated. The VOT method was compared against an augmented Hurst orientation transform (HOT) method using paired t tests, intraclass correlation coefficients (ICCs) and coefficients of variation (CVs%). Longitudinal sensitivity to OA bone changes was not assessed. Results: For the reproducibility of texture parameters, ICCs were >0.75 and CVs% were
