Background: With regard to the high prevalence of osteoarthritis and importance of its classification we evaluated the association between the severity of clinical signs, level of pain and function of joints, and radiological classification.

Materials and Methods : This cross sectional study evaluated 100 knee osteoarthritis patients who were diagnosed by ACR (American College of Rheumatology) criteria. It was performed in Bagyiatallah Hospital in Iran during 2003-2004. In clinical evaluation, Lequesne’s index of pain and function were used. Knee radiographies were classified using Kellgrn-Lawerence. The results were analyzed statistically through chi-square test.

Results: There were 84 females and 16 males (mean age: 52 years old) in this study. The results of clinical classification were as follow: mild (10%), moderate (21%), severe (58%), and very severe (11%). The results of radiological classification were as follow: normal (12%), suspicious (0%), mild (25%), moderate (47%), and severe (16%). There was no significant association between clinical and radiological classifications (p=0.104). There was also no significant difference between males and females (p>0.2).

Conclusions: There was no significant association between clinical classification and radiological grading.