OBJECTIVETo study the relationship between clinical syndromes and X-ray manifestation of knee osteoarthritis (KOA), so as to provide evidence for clinical diagnosis and treatment.

METHODSSeventy-eight patients (108 knees) with KOA from out-patient clinic of orthopedic were collected, aged from 41 to 77, including 65 females (89 knees) and 13 males (19 knees). Questionnair investigation of Lequesne index was performed among all these patients and the Lequesne index was calculated. And all these patients were divided into two groups, mild group (Lequesne index < or = 8) and severe group (Lequesne index > 8). Weight-bearing anteriorposterior and lateral plain film of knee joint and patellofemoral Skyline plain flim was taken. Joint space narrowing, osteophyte formation, subchondral osteosclerosis and subchondral cystic degeneration were evaluated. The lower limb alignment and lateral patella angle were detected. The correlation of the Lequesne index and X-ray manifestation was analyzed by logistic regression analysis.

RESULTSThere were significant differences between mild and severe groups in the following indexes: lateral tibiofemoral joint space narrowing, the medial retropatellar space narrowing, medial and lateral tibia osteophytes, medial and tibial femur femur osteophytes, medial and lateral trochlea osteophytes, lateral patella osteophytes, tibia introcondylar osteophytes (P<0.05). The results of the logistic regression analysis showed that the lateral femur osteophytes were the most important radiologic manifestation to evaluate the severity degree of KOA,with the minimum associated probability (0.009) and the maximum wald value (6.779).

CONCLUSIONWhen evaluating the severity degree of KOA,the joint space narrowing and osteophytes are the most sigenificant radiologic manifestation which includs the lateral tibiofemoral joint space narrowing, the medial retropatellar space narrowing, medial and lateral tibia osteophytes, medial and lateral femur osteophytes, medial and lateral trochlea osteophytes, lateral patella osteophyte, tibial intercondylar osteophyte.