Association of pain with radiological changes in different compartments and views of the knee joint

The aim of this study was to examine the association between radiological patellofemoral and tibiofemoral osteoarthritis and knee symptoms in a population-based survey. Two hundred and fifty unrelated, normal individuals (500 knees) were included in the study. Anteroposterior (AP), lateral and skyline radiographs on each individual were graded for joint space narrowing and osteophytes using a standard atlas. Radiographic features were assessed on their ability to predict knee pain for 15 or more days in the last month, the last year or pain 'ever'. The presence of osteophytes had the strongest association with knee pain 'ever' with an odds ratio (95% Cl) for skyline osteophytes of 7.56 (3.84-14.81) and anteroposterior osteophytes of 5.00 (2.40-10.43). The presence or absence of joint space narrowing in all the radiological views (AP, lateral and skyline) was not significantly associated with knee pain, but there was a trend for an association with severity of narrowing in the lateral and skyline views. The presence of osteophytes in all knee views (AP, lateral or skyline) was best at predicting knee pain in the last year. Osteophytes predict pain more accurately than narrowing on all knee radiographic views (AP lateral or skyline). Pain in the last year (defined as two or more episodes of pain, each lasting for at least 15 days and not related to recent trauma) is predicted more accurately than pain in the last month or ever having had an episode of knee pain and is a useful symptom for inclusion in population studies.