To compare the sensitivity of standard and macro-radiography for quantifying cancellous bone differences between subjects with and without medial compartment knee osteoarthritis (OA).
Patients with medial compartment knee OA (n=24) and non-OA reference subjects (n=10) had a standard and a macro-radiograph (x4 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.
Compared to non-OA, FSA of vertical trabeculae in macro-radiographs increased significantly (P<0.05) in the OA group at several trabecular widths (0.30-0.60mm, 0.7 mm, 0.98-1.14 mm) and in standard radiographs at a single trabecular width (0.48 mm).
Compared 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.