Research Article

Effect of Autologous Platelet Rich Fibrin on the Healing of Experimental Articular Cartilage Defects of the Knee in an Animal Model

Table 2

O’Driscoll histological cartilage repair score.

CharacteristicsScore

Nature of predominant tissue
 Cellular morphology
  Hyaline articular cartilage4
  Incompletely differentiated mesenchyme2
  Fibrous tissue or bone0
 Safranin-O staining of the matrix
  Normal or nearly normal3
  Moderate2
  Slight1
  None0
Structural characteristics
 Surface regularity
  Smooth and intact3
  Superficial horizontal lamination2
  Fissures 25–100% of the thickness1
  Severe disruption including fibrillation0
 Structural integrity
  Normal2
  Slight disruption including cysts1
  Severe disintegration0
 Thickness
  100% of normal adjacent cartilage2
  50–100% of normal cartilage1
  0–50% of normal cartilage0
 Bonding to the adjacent cartilage
  Bonded at both ends of graft2
  Bonded at one end or partially at both ends1
  Not bonded0
Freedom from cellular changes of degeneration
 Hypocellularity
  Normal cellularity3
  Slight hypocellularity2
  Moderate hypocellularity1
  Severe hypocellularity0
 Chondrocyte clustering
  No clusters2
  <25% of the cells1
  25–100% of the cells0
Freedom from degenerative changes in adjacent cartilage
 Normal cellularity, no clusters, and normal staining3
 Normal cellularity, mild clusters, and slight staining2
 Mild or moderate hypocellularity, slight staining1
 Severe hypocellularity, poor or no staining0
Total24