Is Patellofemoral Osteoarthritis Common in Middle‐Aged People With Chronic Patellofemoral Pain?

Rana S. Hinman, Jonathan Lentzos, Bill Vicenzino, Kay M. Crossley

Objective: To document the prevalence of radiographic OA in the medial and lateral patellofemoral joint (PFJ) compartments relative to prevalence of tibiofemoral joint (TFJ) OA in middle-aged and older adults with chronic patellofemoral knee pain. Methods: A convenience sample of 224 people who volunteered for a clinical trial underwent weight-bearing postero-anterior and skyline knee radiographs of their most symptomatic eligible knee. Radiographic severity in the TFJ, and medial and lateral PFJ compartments, was independently graded by two examiners using the Kellgren & Lawrence grading system. Grades 2 and above were considered evidence of OA. Results: OA was common in this cohort and the most prevalent pattern was combined TFJ and PFJ OA (n=98, 43%), followed by isolated PFJ OA (n=57, 25%). Isolated TFJ OA was rare. Overall, more people demonstrated radiographic OA in the PFJ (n=155, 69%) than the TFJ (n=100, 45%). The majority of people with PFJ OA had OA in both the medial and lateral PFJ compartments (n=98, 63%). Even in people under 50 years, radiographic OA was common (isolated PFJ OA, 26% (n=21); and combined TFJ and PFJ OA, 29% (n=23)). Severity of PFJ OA was similar across males and females. Conclusion: PFJ OA was highly prevalent, more so than TFJ OA, and even in individuals aged under 50 years. Further research is needed to elucidate the cause and effect relationship between chronic patellofemoral pain and PFJ OA. © 2013 American College of Rheumatology.