Methods: Thirty patients with unilaterally symptomatic knee OA, based on American College of Rheumatology (ACR) guidelines, were enrolled in the study. The asymptomatic but radiographically osteoarthritic knee of the patients was used as the control knee. The severity of knee pain, stiffness, and disability were determined with the WOMAC index. The severity of OA in plain X-ray was graded using Kellgren-Lawrence (K-L) scale. We also measured the mean articular cartilage thickness with ultrasonography in medial and lateral tibiofemoral joint.

Results: The results showed no correlation between WOMAC scores and the severity of OA on K-L scale (P > 0.05). The results also failed to show any statistically significant correlation between WOMAC scores and articular cartilage thickness in ultrasonography (P > 0.05). On the other hand, in comparing symptomatic and control knees, articular cartilage thickness in the control knees was more than symptomatic knee and the severity of OA based on K-L scale in the symptomatic knee was higher than control knee (P < 0.05).

Conclusion: Although this study did not show any correlation between WOMAC score and articular cartilage thickness or K-L scale, the severity of knee OA based on K-L scale was significantly higher and articular cartilage thickness was significantly lesser in symptomatic knee when compared with control knee.