Is radiology a determinant of pain, stiffness, and functional disability in knee osteoarthritis? A cross-sectional study.

BACKGROUND AND PURPOSES

Discordance between clinical and radiological profiles in knee osteoarthritis has been reported. We hypothesized that the discordance could be due to limited radiological variables studied. This study essentially analyzed many more radiological features than previous studies in order to seek an association between clinical and radiographic features.

METHODS

One hundred and eighty patients with knee osteoarthritis were enrolled as per the American College of Rheumatology (ACR) guidelines. Visual analog scale (VAS) for knee pain and the knee-specific Western Ontario Mac University (WOMAC) index for pain, stiffness, and disability were recorded. Five additional radiological features apart from those in the Kellgren-Lawrence (KL) classification grading system were recorded by two authors who were blinded to the clinical diagnosis. The variables significantly associated were analyzed by linear regression model.

RESULTS

Pain was significantly associated with increasing KL grades; physical function was nearly significant and stiffness was not. On analysis of individual radiological features, WOMAC pain was significant with subchondral sclerosis, joint space width, and tibiofemoral alignment although the correlation was week. VAS pain was significant with the latter two and with articular incongruity. Functional disability was associated with medial joint-space narrowing, tibiofemoral alignment, loose bodies, and juxta-articular osteopenia. However, in the linear regression model, pain and stiffness were significantly associated with articular incongruity and functional disability and total clinical scores with juxta-articular osteopenia.

CONCLUSION

When the radiological features were extended beyond those included in KL grades, pain, stiffness, and disability correlated well with radiography; articular incongruity with pain and stiffness; and juxta-articular osteopenia with physical disability and clinical severity.