The Association Between Gonarthrosis Pain Severity and Radiographic Findings on X-Ray: A Cross-Sectional Study

Knee osteoarthritis (KOA) is a degenerative joint disease that progresses over time due to articular cartilage loss. Orthopedic surgeons use plain radiography (X-ray) with an anteroposterior (AP) standing (weight-bearing) view, which is currently considered the gold standard modality, to diagnose KOA. They base this diagnosis on the clinical history and physical examination of the knee joint. However, many previous studies have reported a weak correlation between knee-joint structural abnormalities on X-rays and described pain. Therefore, our study aimed to assess the incompatibility between patients' pain-severity complaints and radiographic findings on standing AP view. No similar study has been recently published in the Middle East.

158 participants were selected for the study from King Abdulaziz University Hospital, Jeddah, between March 2022 and August 2022. We graded the patients' AP knee radiographs using the Kellgren-Lawrence (KL) grading scale and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, by which we made phone calls to assess pain severity on a 0-10 pain subscale.

We found a significant association between the 0-10 pain subscale and WOMAC questions describing difficulty in sitting (p < 0.05). Comparing KL scores on X-ray on a 0-10 pain subscale, we found a significant association between mild pain and severe radiological findings on X-ray and vice versa. In addition, the comparison between KL scores on X-ray and WOMAC questions describing difficulty in sitting showed a significant association between moderate difficulty in sitting and severe radiological findings and vice versa.

Our results indicated that there was a significant relationship between mild pain and severe radiological findings on X-rays and vice versa. Additionally, there was a significant relationship, based on the KL score and the WOMAC item that assessed sitting difficulty, between moderate sitting difficulty and severe radiological findings and vice versa. This may suggest that central and peripheral sensitization could be one factor in the causes of pain.