Research Article

Exosomes from Kartogenin-Pretreated Infrapatellar Fat Pad Mesenchymal Stem Cells Enhance Chondrocyte Anabolism and Articular Cartilage Regeneration

Table 2

The modified O’Driscoll histologic score.

CharacteristicScore

% hyaline cartilage80–1008
60–806
40-604
20-402
0-200
Structural characteristics
 Surface irregularitySmooth and intact2
Fissures1
Severe disruption, fibrillation0
 Structural integrityNormal2
Slight disruption, including cysts1
Severe lack of integration0
 Thickness100% of normal adjacent cartilage2
50% to 100% or thicker than normal1
0–50%0
 Bonding to adjacent cartilageBonded at both ends of graft2
Bonded at one end/partially both ends1
Not bonded0
Freedom from cellular changes of degenerationNormal cellularity, no clusters2
Slight hypocellularity, <25% chondrocyte clusters1
Moderate hypocellularity, >25% clusters0
Freedom from degenerate changes in adjacent cartilageNormal cellularity, no clusters, normal staining3
Normal cellularity, mild clusters, moderate staining2
Mild or moderate hypocellularity, slight staining1
Severe hypocellularity, slight staining0
Reconstitution of subchondral boneComplete reconstitution2
Greater than 50% reconstruction1
50% or less reconstruction0
Bonding of repair cartilage to de novo subchondral boneComplete and uninterrupted2
<100% but >50% reconstruction1
<50% complete0
Safranin O staining>80% homogeneous positive stain2
40%–80% homogeneous positive stain1
<40% homogeneous positive stain0
Total scoreMax 27