The primary efficacy endpoint is the Thompson articular index (THOMP) sum of scores for each knee joint, of pain on movement (0-3), soft tissue swelling (0-3) and warmth (0-3); (range 0-9). Secondary endpoints are: the Knee joint articular index (KJAI): the sum of the tenderness scores (0-3), joint swelling (0-3), the ballottement of patella or the "bulge sign" (0-2), and range of knee joint flexion (0-3) and extension (0-3) (KJAI, range 0-14). Standard joint evaluation comprise: the 66/68 swollen joint number (SJN) and tender joint number (TJN) (0-1); a modified Ritchie articular index (RAI), by assessment of 30 joints for tenderness (0-3) (range: 0-90), (including hand and foot distal interphalangeal joints (DIP) of each side as a group; the pain visual analogue scale (VAS) (0-100mm), the health assessment questionnaire (HAQ)- disability index (0-3) and the SF36 (range 0-24) at the above time points.