OBJECTIVETo explore the diagnostic value of whole-organ magnetic resonance imaging score (WORMS) in knee osteoarthritis (KOA).

METHODSFrom November 2009 to January 2011,70 patients with KOA combined with knee effusion among outpatient and inpatient were analyzed retrospectively. Among the patients, 12 patients were male, 58 patients were female,ranging in age from 46 to 75 years,with a mean age of (59.66 +/- 9.93) years. The clinical symptoms were evaluated by WOMAC, the imaging of KOA was assessed by K-L score and WORMS, and COMP and CTX- II were measured respectively by ELISA. The correlation analyses and multiple linear regression analysis were studied to determine associations among biomarkers, clinical variables and radiographic findings of knee joints.

RESULTSThe average scores of WOMAC and WORMS were (57.50 +/- 8.20) and (64.54 +/- 16.45) respectively. The median of CTX- II nd COMP were 2.42 ng/ml and 4.56 ng/ml respectively. Grouped by less than the lowest quartile and more than the highest quartile of WORMS, COMP was significantly different (Z=2.04, P=0.039), but there was no significant difference in CTX-II (Z=0.79, P=0.427). WORMS were positively correlated with WOMAC and K-L score (r=0.777, P<0.01; r=0.716, P<0.01; respectively); WOMAC was also positively correlated with K-L score (r=0.692, P<0.01). WORMS's cartilage, osteophytes and synovitis were positively correlated with WOMAC, K-L score and COMP respectively (r=0.771, P<0.01; r=0.509, P<0.01; r=0.917, P<0.01). It was determined by stepwise regression that the KOA was mainly affected by WORMS, K-L score (P=0.015, P=0.025 respectively) when WOMAC as a dependent variable, age, gender, K-L score, WORMS, COMP and CTX- II as independent variables (F=20.327, P<0.01).

CONCLUSIONWORMS has a better reference value for diagnosis of KOA. The expression of COMP is high in the synovial fluid when WORMS at the high point. The clinical symptoms of knee osteoarthritis are mainly affected by WORMS and K-L score.