Table 2

Modified O’Driscoll histological and histochemical grading scale
Score
Nature of the predominant tissue
Cellular morphology
  Hyaline articular cartilage 4
  Incompletely differentiated mesenchyme 2
  Fibrous tissue or bone 0
Safranin-O staining of the matrix
  Normal or nearly normal 3
  Moderate 2
  Slight 1
  None 0
Structural characteristics
Surface regularity
  Smooth and intact 3
  Superficial horizontal lamination 2
  Fissures - 25 to 100% of the thickness 1
  Severe disruption, including fibrillation 0
Structural integrity
  Normal 2
  Slight disruption, including cysts 1
  Severe disintegration 0
Thickness
  100% of normal adjacent cartilage 2
  50 to 100% of normal cartilage 1
  0 to 50% of normal cartilage 0
Bonding to the adjacent cartilage
  Bonded at both ends of graft 2
  Bonded at one end, or partially at both ends 1
  Not bonded 0
Freedom from cellular changes of degeneration
Hypocellularity
  Normal cellularity 3
  Slightly hypocellularity 2
  Moderate hypocellularity 1
  Severe hypocellularity 0
Chondrocyte clustering
  No clusters 2
  <25% of the cells 1
  25 to 100% of the cells 0
Freedom from degenerative changes in adjacent cartilage
Normal cellularity, no clusters, normal staining 3
Normal cellularity, mild clusters, moderate staining 2
Mild or moderate hypocellularity, slight staining 1
Severe hypocellularity, poor or no staining 0

Nam et al.

Nam et al. Arthritis Research & Therapy 2013 15:R129   doi:10.1186/ar4309

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