Differences in trabecular structure between knees with and without osteoarthritis quantified by macro and standard radiography, respectively

SummaryObjectiveTo compare the sensitivity of standard and macro-radiography for quantifying cancellous bone differences between subjects with and without medial compartment knee osteoarthritis (OA).MethodsPatients with medial compartment knee OA (n = 24) and non-OA reference subjects (n = 10) had a standard and a macro-radiograph (×4 magnification) of one knee. Fractal Signature Analysis (FSA), a computerised image analysis technique, measured differences in cancellous bone structure between OA and non-OA tibiae in all radiographs.ResultsCompared to non-OA, FSA of vertical trabeculae in macro-radiographs increased significantly (P < 0.05) in the OA group at several trabecular widths (0.30–0.60 mm, 0.78 mm, 0.98–1.14 mm) and in standard radiographs at a single trabecular width (0.48 mm).ConclusionCompared to standard radiography, increased spatial resolution of macro-radiography allowed greater detection of trabecular bone differences between OA and non-OA knees. Nonetheless, difference was also detected in standard radiographs.