Figure 1.

Sagittal section through the medial femoral condyles of rat (10X).(A) Normal articular cartilage structures showing smooth articular surface, normal chondrocytes with columnar orientation, intact tide mark and subchondral bone (Mankin score - 0). (B) At 2 weeks post-ACLT, a confined area of cartilage destruction was observed as reflected by the irregularity of the articular surface and moderately reduced chondrocyte numbers. The tidemark remained visible and the subcondral bone remained intact (Mankin score - 10). (C) At 2 weeks post-MIA injection, more destructive changes over the femoral condyle was observed, with the loss of articular cartilage integrity, moderate to severe reduction in chondrocytes that appear to be necrotic and largely dispersed. The tide mark was not clearly visible (Mankin score -11).