Table 1

Definitions of subsets of symptomatic radiographic knee OA

'Any OA'

'Moderate to severe OA'

PFJOA

Skyline K&L ≥2

Skyline K&L ≥3

OR

OR

Lateral osteophytes ≥1

Lateral osteophytes = 3

TFJOA

PA K&L ≥2

PA K&L ≥3

OR

OR

Posterior osteophytes ≥1

Posterior osteophytes = 3

K&L Kellgren and Lawrence score; OA Osteoarthritis; PA Posteroanterior; PFJ Patellofemoral joint; TFJ Tibiofemoral joint

Peat et al. Arthritis Research & Therapy 2012 14:R63   doi:10.1186/ar3779