Table 1.

Overview of the different grades of the OARSI and AHO score

	Scores
Grade	OARSI [39]	AHO [41]
0		No evident subchondral bone sclerosis, articular cartilage directly connected to the bone
1	Cartilage surface intact	Some subchondral sclerosis, bone volume increased, cartilage contact with the bone marrow
2	Cartilage surface discontinuity	Distinct increase in subchondral sclerosis and bone volume, fibrillation in subchondral bone, no contact of the bone marrow to the articular cartilage
3	Vertical fissures within the cartilage	Late-stage disease, severe subchondral sclerosis and massively increased bone volume, bone marrow distance from the cartilage increases
4	Erosion
5	Denudation
6	Deformation