Fig. 1

Methodological process consists of converting computed tomography (CT) grayscale intensities to bone mineral density (BMD) using a quantitative CT (QCT) reference phantom (a), followed by building two imaged volumes for each tibia, one with manual correction at the epiphyseal line and one using the full tibia (b). Imaged volumes were divided into lateral and medial regions (c) and then the outer 2.5-mm and subchondral 7.5-mm depth were removed from each imaged volume (d). BMD measurements included epiphyseal BMD between the epiphyseal line and 7.5 mm from the subchondral surface and metaphyseal BMD 10 mm distal from the epiphyseal line (e)