Outerbridge Classification of Cartilage defects

Courtesy: Christopher McCrum, UT SouthWestern, Dallas, Texas, USA

Outerbridge Bentley Classification:

• Grade I lesion: articular surfaces that are swollen, soft, and in some cases blistered.
• Grade II lesions: characterized by articular fissures and clefts with diameters <1 cm.
• Grade III lesions: deep fissures extending to subchondral bone with diameters >1 cm.
• Grade IV lesions: include those with exposed subchondral bone.