To examine the association between self-reported knee pain and radiographic features of osteoarthritis (OA) of the knee.
A sample of participants in the Baltimore Longitudinal Study of Aging (452 Caucasian males and 223 Caucasian females) completed questionnaires and underwent a standing radiograph of both knees at the same biennial visit between 1984 and 1989. Radiographs were interpreted using both the Kellgren-Lawrence and individual features scales. Odds ratios were calculated for the association of radiographic features with knee pain after adjustment for age, sex, and body mass index.
Overall, 156 (23%) persons reported ever having knee pain, and 104 (15%) reported current knee pain (within the previous year). Both ever knee pain and current knee pain were significantly associated with the presence of definite knee OA (Kellgren-Lawrence grade > or = 2) and with the presence of all individual features. There was a direct relationship between all measures of severity of radiographic OA and knee pain.
These data demonstrate that radiographic features of knee OA are significantly associated with knee pain. The data also support the continued use of the Kellgren-Lawrence grading scale for defining knee OA in population studies.