Relation of Patellofemoral Joint Alignment, Morphology, and Radiographic Osteoarthritis to Frequent Anterior Knee Pain: Data from the Multicenter Osteoarthritis Study

Objective Patellofemoral ( PF ) alignment and trochlear morphology are associated with PF osteoarthritis ( OA ) and knee pain, but whether they are associated with localized anterior knee pain is unknown, which is believed to be a symptom specific to PF joint pathology. We therefore aimed to evaluate the relation of PF alignment and morphology, as well as PFOA and tibiofemoral OA , to anterior knee pain. Methods The Multicenter Osteoarthritis Study is a cohort study of individuals with, or at risk for, knee OA . We evaluated cross‐sectional associations of PF alignment, trochlear morphology, and PF and tibiofemoral radiographic OA , with localized anterior knee pain (defined with a pain map). We used 2 approaches: a within‐person knee‐matched evaluation of participants with unilateral anterior knee pain (conditional logistic regression), and a cohort approach comparing those with anterior knee pain to those without (binomial regression). Results With the within‐person knee‐matched approach (n = 110; 64% women, mean age 70 years, body mass index [ BMI ] 30.9), PF alignment, morphology, and tibiofemoral OA were not associated with unilateral anterior knee pain. Radiographic PFOA was associated with pain, odds ratio 5.3 (95% confidence interval [95% CI ] 1.6–18.3). Using the cohort approach (n = 1,818; 7% of knees with anterior knee pain, 59% women, mean age 68 years, BMI 30.4), results were similar: only PFOA was associated with pain, with a prevalence ratio of 2.2 (95% CI 1.4–3.4). Conclusion PF alignment and trochlear morphology were not associated with anterior knee pain in individuals with, or at risk for, knee OA . Radiographic PFOA , however, was associated with pain, suggesting that features of OA , more so than mechanical features, may contribute to localized symptoms.