From: Levels of neuropeptide Y in synovial fluid relate to pain in patients with knee osteoarthritis
Stage | Grade | Standing x-ray |
---|---|---|
0 | Normal | |
Early stage | 1 | Bone sclerosis or osteophyte formation |
Middle stage | 2 | Narrowing of joint space (≤3 mm) |
3 | Obliteration of joint space or subluxationb | |
Advanced stage | 4 | Defect of tibial plateau (<5 mm) |
5 | Defect of tibial plateau (≥5 mm) |