Knee OA diagnostic criteria 1, recurrent knee pain within the last 1 month 2, X-ray (standing or weight-bearing position) shows narrowing of joint space, subchondral bone sclerosis and/or cystic changes, and bone redundancy formation at the joint edge 3, clear and viscous joint fluid (at least 2 times), WBC <2000/mL 4, middle-aged and elderly patients (/ >40 years old) 5, morning stiffness ≤30 min 6, bone rubbing sound (sensation) during activity Note. Comprehensive clinical, laboratory and X-ray examinations, meeting 1+2 or 1+3+5+6 or 1+4+5+6, can diagnose knee OA Hip OA diagnostic criteria 1, recurrent hip pain in the past 1 month 2, hematocrit ≤20 mm/h 3, X-ray film shows bone superfluous formation, acetabular rim hyperplasia 4, X-ray film shows narrowing of hip joint space Note: Meeting diagnostic criteria 1+2+3 or 1+3+4 If the diagnostic criteria are met, hip OA can be diagnosed