Chondral Injury Classification

Normal Articular Cartilage

• ICRS Grade 0: normal

1. Normal articular cartilage on inferior pole of the patella
2. Trochear groove of distal femur

• ICRS Grade 1: Nearly Normal (soft indentation and/or superficial fissures and cracks
• Outerbridge Grade I: Softening and swelling of cartilage
• Noyes Grade 1: Cartilage surface intact (1A = some remaining resilience; 1B = deformation)

1. Soft indentation and superficial fissures on inferior pole of the patella
2. Trochear groove of distal femur

• ICRS Grade 2: Abnormal (lesions extending down to <50% of cartilage depth
• Outerbridge Grade II: Fragmentation and fissuring, less than 0.5-in diameter
• Noyes Grade 2A: Cartilage surface damaged (cracks, fibrillation, fissuring, or fragmentation); with less than half of cartilage thickness involved

1. Fragmentation and fissuring extending down <50% of the depth of the cartilage on the medial facet and inferior pole of the patella
2. Trochear groove of distal femur

• ICRS Grade 3: Severly Abnormal (carilage defects >50% of cartilage depth
• Outerbridbe Grade III: Fragmentation and fissuring, greater than 0.5-in diameter
• Noyes Grade 2B: Depth of involvement greater than half of cartilage thickness but without exposed bone

1. Fragmentation and fissuring extending down >50% of the depth of the cartilage on the medial facet of the patella
2. Trochear groove of distal femur

• ICRS Grade 4: Severly abnormal (through the subchondral bone)
• Outerbridge Grade IV: Erosion of cartilage down to exposed subchondral bone
• Noyes Grade 3: Bone exposed (3A = surface intact; 3B = surface cavitation)

1. Erosion of cartilage down to exposed subchondral bone on the lateral facet of the patella
2. Trochear groove of distal femur