Back Propagation Neural Network-Based Ultrasound Image for Diagnosis of Cartilage Lesions in Knee Osteoarthritis

Table 1

Staging criteria of knee cartilage degeneration under arthroscopy.

Stage	The state of cartilage lesions
Stage I	The cartilage tissue loses its luster and becomes hard in texture
Stage II	The surface of the cartilage is not smooth, with blisters or velvet-like changes, and the invasion range of the damage is less than 1/2 of the depth of the cartilage.
Stage III	The cartilage lesions are severe, with local thinning or even fibrosis, and the invasion range of the injury is more than 1/2 of the cartilage depth.
Stage IV	The cartilage has ulcerated lesions, complete defects, and exposed subchondral bone tissue.