title: Structural Abnormalities on Magnetic Resonance Imaging in Patients With Patellofemoral Pain: A Cross-sectional Case-Control Study.
abstract: Structural abnormalities of the patellofemoral joint might play a role in the pathogenesis of patellofemoral pain (PFP), a common knee problem among young and physically active individuals. No previous study has investigated if PFP is associated with structural abnormalities of the patellofemoral joint using high-resolution magnetic resonance imaging (MRI).
  
  
  
  To investigate the presence of structural abnormalities of the patellofemoral joint on high-resolution MRI in patients with PFP compared with healthy control subjects.
  
  
  
  Cross-sectional study; Level of evidence, 3.
  
  
  
  Patients with PFP and healthy control subjects between 14 and 40 years of age underwent high-resolution 3-T MRI. All images were scored using the Magnetic Resonance Imaging Osteoarthritis Knee Score with the addition of specific patellofemoral features. Associations between PFP and the presence of structural abnormalities were analyzed using logistic regression analyses adjusted for age, body mass index (BMI), sex, and sports participation.
  
  
  
  A total of 64 patients and 70 control subjects were included in the study. Mean ± SD age was 23.2 ± 6.4 years, mean BMI ± SD was 22.9 ± 3.4 kg/m(2), and 56.7% were female. Full-thickness cartilage loss was not present. Minor patellar cartilage defects, patellar bone marrow lesions, and high signal intensity of the Hoffa fat pad were frequently seen in both patients (23%, 53%, and 58%, respectively) and control subjects (21%, 51%, and 51%, respectively). After adjustment for age, BMI, sex, and sports participation, none of the structural abnormalities were statistically significantly associated with PFP.
  
  
  
  Structural abnormalities of the patellofemoral joint have been hypothesized as a factor in the pathogenesis of PFP, but the study findings suggest that structural abnormalities of the patellofemoral joint on MRI are not associated with PFP.
authors.affiliation: Department of General Practice, Erasmus MC, University Medical Center, Rotterdam, the Netherlands Department of Radiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Rianne A
authors.initials: RA
authors.lastname: van der Heijden
authors.affiliation: Department of Radiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands Department of Radiology, Rijnstate Hospital, Arnhem, the Netherlands.
authors.forename: Janneke L M
authors.initials: JL
authors.lastname: de Kanter
authors.affiliation: Department of General Practice, Erasmus MC, University Medical Center, Rotterdam, the Netherlands Department of Orthopedic Surgery, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Sita M A
authors.initials: SM
authors.lastname: Bierma-Zeinstra
authors.affiliation: Department of Orthopedic Surgery, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
authors.affiliation: Department of Sports Medicine, Medical Center Haaglanden, Leidschendam, the Netherlands.
authors.forename: Peter L J
authors.initials: PL
authors.lastname: van Veldhoven
authors.affiliation: Department of Radiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: Krestin
authors.affiliation: Department of Radiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Edwin H G
authors.initials: EH
authors.lastname: Oei
authors.affiliation: Department of General Practice, Erasmus MC, University Medical Center, Rotterdam, the Netherlands m.vanmiddelkoop@erasmusmc.nl.
authors.forename: Marienke
authors.initials: M
authors.lastname: van Middelkoop
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D057071:Patellofemoral Joint / Q000002:abnormalities*; D046788:Patellofemoral Pain Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D055815:Young Adult
keywords: knee; magnetic resonance imaging (MRI); patella; patellofemoral pain syndrome