title: Incidental magnetic resonance imaging signal changes in the extensor carpi radialis brevis origin are more common with age.
abstract: BACKGROUND
  Patients with enthesopathy of the extensor carpi radialis brevis (ECRB) demonstrate signal changes on magnetic resonance imaging (MRI). It is likely that these MRI changes persist for many years or may be permanent, regardless of symptoms, and represent an estimation of disease prevalence. We tested the hypothesis that the prevalence of incidental signal changes in the ECRB origin increases with age.
  
  
  METHODS
  We searched MRI reports of 3374 patients who underwent an MRI scan, including the elbow, for signal changes in the ECRB origin. Medical records were reviewed for symptoms consistent with ECRB enthesopathy. Prevalences of incidental and symptomatic signal changes were calculated and stratified by age. We used multivariate logistic regression analysis to test whether age, sex, and race were independently associated with ECRB enthesopathy and calculated odds ratios.
  
  
  RESULTS
  Signal changes in ECRB origin were identified on MRI scans of 369 of 3374 patients (11%) without a clinical suspicion of tennis elbow. The prevalence increased from 5.7% in patients aged between 18 and 30 years up to 16% in patients aged 71 years and older. Older age (odds ratio, 1.04; P <.001) was independently associated with the incidental finding of ECRB enthesopathy on elbow MRI scans.
  
  
  CONCLUSIONS
  Increased MRI signal in the ECRB origin is common in symptomatic and in asymptomatic elbows. Our findings support the concept that ECRB enthesopathy is a highly prevalent, self-limited process that seems to affect a minimum of 1 in approximately every 7 people.
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Wouter F
authors.initials: WF
authors.lastname: van Leeuwen
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Stein J
authors.initials: SJ
authors.lastname: Janssen
authors.affiliation: Department of Surgery and Perioperative Care, Dell Medical School, The University of Texas at Austin, Austin, TX, USA. Electronic address: david.ring@austin.utexas.edu.
authors.forename: David
authors.initials: D
authors.lastname: Ring
authors.affiliation: Hand and Upper Extremity Service, Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Neal
authors.initials: N
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D004550:Elbow / Q000000981:diagnostic imaging*; D004551:Elbow Joint / Q000000981:diagnostic imaging*; D000070676:Enthesopathy / Q000000981:diagnostic imaging*; D005260:Female; D005542:Forearm; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D013716:Tennis Elbow / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Extensor carpi radialis brevis; MRI; enthesopathy; lateral epicondylitis; prevalence; tennis elbow