Fig. 1

a and b show two-dimensional micro-computed tomography (μCT) images of the proximal tibia from sham control (Sham) (a) and medial meniscectomy vehicle-treated (MM + veh) rats (b). Red line indicated the area of cancellous bone evaluation at tibial epiphysis (e) and metaphysis (m). Arrowhead points at the osteophyte. c and d show EPIC μCT images of the same tibias depicted in (a) and (b). The red arrow indicates normal articular cartilage whereas the dotted arrow indicates osteoarthritic cartilage. e and f show larger EPIC μCT images of the articular cartilage. The length of the medial tibial plateau was measured for each sample and then divided into three zones ranging from 0.8 to 1.0 mm in length. Zone 1 (Z1) was placed on the outside of the medial edge of the joint and Zone 3 (Z3) on the inside of the tibial plateau adjacent to the central collateral ligaments. Zones are delineated by dotted lines. The red arrow indicates normal articular cartilage whereas the dotted arrow indicates osteoarthritic cartilage