Objectives: Joint pain and radiographic osteoarthritis are often discordant.
Aim: To investigate this issue more closely by studying the detailed nature of pain and disability, and how this relates to radiographic osteoarthritis.
Methods: Population-based study of 819 adults aged >or=50 years with knee pain. The severity of knee pain, stiffness and disability was measured using a validated scale (the Western Ontario and McMaster Universities (WOMAC) Score) and pain persistence was recorded. Global severity was measured by the graded chronic pain scale. Three radiographic views of the knees were obtained-weight-bearing posteroanterior metatarsophalangeal, supine skyline and supine lateral.
Results: 745 participants with knee pain in the past 6 months were eligible (mean age 65 years, 338 men). Radiographic osteoarthritis was more common in those with a longer history and more persistent symptoms. A strong trend was found of radiographic osteoarthritis being more strongly associated with higher WOMAC scores for pain severity, stiffness and disability (adjusted odds ratio (95% confidence interval (CI)) for highest v lowest WOMAC category: 3.7 (2.0 to 6.7), 3.0 (2.0 to 4.6) and 2.8 (1.6 to 5.0), respectively). Those individual WOMAC items for pain and disability pertaining to weight-bearing mobility were the most strongly associated with radiographic osteoarthritis. Combining pain persistence and global severity, persistent severe pain was associated with a significant increase in the occurrence of radiographic osteoarthritis (2.6 (95% CI 1.5 to 4.7)).
Conclusions: A consistent association was found between severity of pain, stiffness and physical function and the presence of radiographic osteoarthritis. This study highlights the potential contribution of underlying joint disease to the degree of pain and disability.