Research Article

Influence of Intra-Articular Administration of Trichostatin A on Autologous Osteochondral Transplantation in a Rabbit Model

Table 2

The modified O’Driscoll histology score.

CategoryScore

Nature of predominant tissue
 Cell morphology
  Hyaline 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
   Fissure 25–100% of the thickness1
   Severe disruption0
  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 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
  Normal3
  Slight2
  Moderate1
  Severe0
 Chondrocyte clustering
  No clusters2
  <25% of the cells1
  25–100% of the cells0
Freedom from degeneration changes in adjacent cartilage
 Normal cellularity, no clusters, normal staining3
 Normal cellularity, mild clusters, moderate staining2
 Mild or moderate hypocellularity, slight staining1
 Severe hypocellularity, poor or no staining0