Correlation of Radiologic Findings, Pain Severity, and Functional Status in Patients with Primary Knee Osteoarthritis: A Cross-Sectional Study

Abstract

Background & Objective: Knee osteoarthritis (OA) is one of the leading causes of chronic pain and physical disability worldwide. However, the correlation between its radiographic and clinical severity is not uniform across populations. In South Asia, very little evidence exists in this regard. This study aimed to concisely evaluate the association between radiographic and clinical severity in primary knee OA while identifying key demographic variables linked to disease severity. Methodology: A cross-sectional study was carried out in the Department of Rheumatology at Saidu Group of Teaching Hospitals. 95 patients with knee OA participated in the study. Radiographic severity was assessed through Kellgren–Lawrence (KL) grading applied on anteroposterior knee x-rays. Clinical severity was assessed through WOMAC functional and pain subscales. Independent predictors of the total WOMAC score were identified by a multivariable linear regression analysis. P<0.05 was considered significant. Results: Among the 95 participants, the mean age was 56.84±12.89 years, and 65.3% were female. KL grades 2 and 3 were the most frequently observed radiographic grades, each comprising 32.6% of cases. Median WOMAC pain and functional scores were 10/20 and 34/68, respectively. There were statistically significant differences across radiological grades for WOMAC pain, functional, and total scores (p<0.001). Spearman analysis showed a moderate positive correlation between KL grade and WOMAC pain score (ρ=0.472), and a strong positive correlation was seen with WOMAC functional (ρ=0.613) and total WOMAC scores (ρ=0.612) (all p<0.001). KL grade (6.550, 95% CI: 4.378-8.721, p < 0.001), age (0.335, 95% CI: 0.149-0.522, p = 0.001), and body weight (0.295, 95% CI: -0.457 to -0.133, p < 0.001) were identified as independent predictors of total WOMAC score by multivariable linear regression analysis. Conclusion: Higher radiographic severity correlates with greater pain and poorer function. Clinicians need to evaluate radiographic results as well as patient-reported symptoms to obtain a comprehensive picture of knee OA in clinical practice. Key Words: Primary Osteoarthritis, Pain Severity, Functional Status, Radiological Findings.