Table 1.

Grading systems for arthroscopic classification of cartilage lesions

Author	Grade	Description
Outerbridge [18]	I	Softening or edema
	II	Fragmentation/tear <1/2 in. (~1.3 cm)
	III	Fragmentation/tear <1/2 in. (~1.3 cm)
	IV	Bare open laying subchondral bone
Insall [15]	I	Softening
	II	Deep fissures to the subchondral bone
	III	Fibrillation
	IV	Erosion and exposure of the subchondral bone
Ficat [11]	I	Chondromalacia, surface intact
	II	Chondromalacia, surface with tears or fibrillations
	III	Tear up to the subchondral bone
	IV	Complete ulceration
Casscells [6]	I	Superficial erosions (diameter <1 cm)
	II	Erosions without extension to the subchondral bone or diameter 1–2 cm
	III	Deep erosions up to the subchondral bone or diameter 1–2 cm
	IV	Complete defect or diameter >2 cm
Beguin [2]	I	Swelling and edema
	II	Deep superficial fissures
	III	Deep fissures
	IV	Complete defect with widely uncovered subchondral bone
Bently und Dowd [3]	I	Fibrillation/tear >0.5 cm
	II	Fibrillation/tear 0.5-1 cm
	III	Fibrillation/tear 1–2 cm
	IV	Fibrillation with widely uncovered subchondral bone >2 cm
Noyes und Stabler [17]	I	Intact cartilage
	Ia	Softening <1 cm
	Ib	Softening >1 cm
	II	Fibrillation/tear
	IIa	Fibrillation/tear <half slight of the cartilage layer
	IIb	Fibrillation/tear >half slight of the cartilage layer
	III	Uncovered subchondral bone
	IIIa	Bone normal
	IIIb	Bone cysts or osteophytes
ICRS [5]	0	Normal
	I	Nearly normal (superficial lesions, softening, fissures)
	II	Abnormal (lesions extending to <50% of cartilage depth)
	III	Severely abnormal (lesions extending to >50% of cartilage depth)
	IV	Severely abnormal (complete defect)
SFA [8]	Severe	The severity of cartilage degeneration is determined by a visual analogous scale [ranging 0 (normal) to 100 (severely abnormal, complete defect]
	Size	Percentage (%) of cartilage degeneration within the joint surface
	A	Size (%) of grade I lesions ×0.14
	B	Size (%) of grade II lesions ×0.34
	C	Size (%) of grade III lesions ×0.65
	D	Size (%) of grade IV lesions ×1.00