Table 1.

Effect of PFE administration on the histological assessment of articular cartilage changes in the Post-Traumatic Osteoarthritis model was performed as per OARSI guidelines [39] and the criteria for histological assessment are shown in the table.

Parameter

Safranin O-fast green staining

0 = uniform staining throughout articular cartilage

1 = loss of staining in superficial zone of hyaline cartilage <50% the length of the condyle or plateau

2 = loss of staining in superficial zone of hyaline cartilage ≥50% the length of the condyle or plateau

3 = loss of staining in the upper 2/3's of hyaline cartilage <50% the length of the condyle or plateau

4 = loss of staining in the in the upper 2/3's hyaline cartilage ≥50% the length of the condyle or plateau

5 = loss of staining in all the hyaline cartilage <50% the length of the condyle or plateau

6 = loss of staining in all the hyaline cartilage ≥50% the length of the condyle or plateau

Structure

0 = normal

1 = surface irregularities

2 = fissures in <50% surface

3 = fissures in ≥50% surface

4 = erosion 1/3 hyaline cartilage <50% surface

5 = erosion 1/3 hyaline cartilage ≥50% surface

6 = erosion 2/3 hyaline cartilage <50% surface

7 = erosion 2/3 hyaline cartilage ≥50% surface

8 = Full depth erosion hyaline cartilage <50% surface

9 = Full depth erosion hyaline cartilage ≥50% surface

10 = Full depth erosion hyaline and calcified cartilage to the subchondral bone <50% surface

11 = Full depth erosion hyaline and calcified cartilage to the subchondral bone ≥50% surface

Chondrocyte density

0 = no decrease in cells

1 = focal decrease in cells

2 = multifocal decrease in cells

3 = multifocal confluent decrease in cells

4 = Diffuse decrease in cells

Cluster formation

0 = normal

1 = <4 clusters

2 = ≥4 but <8 clusters

3 = ≥8 clusters

Source: Laverty et al., 2010 [39]