Table 1.

Kellgren–Lawrence grading criteria.

Grade	X-ray Imaging Features
0	Normal
I	The joint gap is suspected to be narrowed; there may be osteophyma
II	Obvious osteophyma; the joint gap is suspected to be narrowed
III	Moderate osteophyma; the joint gap is obviously narrowed with sclerotic change
IV	Massive osteophyma; the joint gap is obviously narrowed with severe sclerotic lesions and obvious deformities