Background: Patellar tendinopathy is a common cause of activity-related anterior knee pain. Evidence is conflicting as to whether obesity is a risk factor for this condition. The aim of this study was to determine the relationship between obesity and prevalence of magnetic resonance imaging (MRI) defined patellar tendinopathy in community-based adults. Methods. 297 participants aged 50-79 years with no history of knee pain or injury were recruited from an existing community-based cohort. Measures of obesity included measured weight and body mass index (BMI), self-reported weight at age of 18-21 years and heaviest lifetime weight. Fat-free mass and fat mass were measured using bioelectrical impedance. Participants underwent MRI of the dominant knee. Patellar tendinopathy was defined on both T1- and T2-weighted images. Results: The prevalence of MRI defined patellar tendinopathy was 28.3 . Current weight (OR per kg = 1.04, 95 CI 1.01-1.06, P = 0.002), BMI (OR per kg/m2= 1.10, 95 CI 1.04-1.17, P = 0.002), heaviest lifetime weight (OR per kg = 1.03, 95 CI 1.01-1.05, P = 0.007) and weight at age of 18-21 years (OR per kg = 1.03, 95 CI 1.00-1.07, P = 0.05) were all positively associated with the prevalence of patellar tendinopathy. Neither fat mass nor fat-free mass was associated with patellar tendinopathy. Conclusion: MRI defined patellar tendinopathy is common in community-based adults and is associated with current and past history of obesity assessed by BMI or body weight, but not fat mass. The findings suggest a mechanical pathogenesis of patellar tendinopathy and patellar tendinopathy may be one mechanism for obesity related anterior knee pain.
Fairley, J., Toppi, J., Cicuttini, F. M., Wluka, A. E., Giles, G. G., Cook, J. L., O'Sullivan, R. M., & Wang, Y. (2014). Association between obesity and magnetic resonance imaging defined patellar tendinopathy in community-based adults: a cross-sectional study. BMC Musculoskeletal Disorders, 15(1 (Art. No.: 266)), 1 - 7. https://doi.org/10.1186/1471-2474-15-266