title: Factors associated with magnetic resonance imaging defined patellar tendinopathy in community-based middle-aged women: a prospective cohort study.
abstract: BACKGROUND
  Patellar tendinopathy identified by imaging modalities has been reported in asymptomatic athletes and associated with tendon-related symptoms. However there is little data in community-based populations. The aim of this cohort study was to examine the prevalence of magnetic resonance imaging (MRI) defined patellar tendinopathy, the factors associated with this condition, and whether it was associated with knee pain in community-based middle-aged women.
  
  
  METHODS
  One hundred seventy six women, aged 40-67 years, with no significant knee pain or injury underwent knee MRI. Patellar tendinopathy was defined on both T1- and T2-weighted fat-saturated MRIs. The cross-sectional area of vastus medialis was measured from MRI. Height and weight were measured to calculate body mass index (BMI). Physical activity was assessed using a questionnaire. Knee pain was assessed using the Western Ontario and McMaster University Osteoarthritis Index.
  
  
  RESULTS
  The prevalence of MRI defined patellar tendinopathy was 30.1%. Higher levels of physical activity (odds ratio 1.65, 95% CI 1.09-2.51) and greater vastus medialis cross-sectional area (odds ratio 1.22, 95% CI 1.04-1.43) were associated with increased prevalence of patellar tendinopathy, independent of age and BMI. The persistence of patellar tendinopathy was associated with the worsening of knee pain over 2 years (odds ratio 10.65, 95% CI 1.14-99.77).
  
  
  CONCLUSIONS
  In community-based middle-aged women MRI-diagnosed patellar tendinopathy is common, with higher levels of physical activity and greater vastus medialis size being risk factors suggesting a biomechanical effect. Persistent patellar tendinopathy is associated with worsening of knee pain. These findings suggest that further work is needed to determine the contribution of patellar tendinopathy on knee pain and function in older people.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. jttoppi@gmail.com.
authors.forename: Jason
authors.initials: J
authors.lastname: Toppi
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. jfairley11@gmail.com.
authors.forename: Jessica
authors.initials: J
authors.lastname: Fairley
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. flavia.cicuttini@monash.edu.
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Cicuttini
authors.affiliation: Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Frankston, VIC, 3199, Australia. jill.cook@monash.edu.
authors.forename: Jill
authors.initials: J
authors.lastname: Cook
authors.affiliation: Women's Health Research Program, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. susan.davis@monash.edu.
authors.forename: Susan R
authors.initials: SR
authors.lastname: Davis
authors.affiliation: Women's Health Research Program, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. robin.bell@monash.edu.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Bell
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. fahad.hanna@monash.edu.
authors.forename: Fahad
authors.initials: F
authors.lastname: Hanna
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. yuanyuan.wang@monash.edu.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D010329:Patella / Q000473:pathology*; D011446:Prospective Studies; D012111:Residence Characteristics; D012307:Risk Factors; D052256:Tendinopathy / Q000175:diagnosis* / Q000453:epidemiology*