title: Knees of Ironman triathletes: magnetic resonance imaging assessment of older (>35 years old) competitors.
abstract: OBJECTIVE
  To use magnetic resonance imaging (MRI) to evaluate the knees of older (>35 years old), competitive Ironman triathletes to determine the prevalence of abnormal findings.
  
  
  METHODS
  The knees of 29 Ironman triathletes (20 men, 9 women; age range, 35-66 years old) were studied by MRI. The findings were analyzed collectively and categorized into group I (N = 13), subjects without prior knee injuries and symptoms, and group II (N = 16), subjects with prior knee injuries and/or current symptoms.
  
  
  RESULTS
  Ten percent of the knees had ligamentous abnormalities, but the prevalence was not statistically different comparing group I to group II. Fifty-five percent had abnormal menisci. The overall prevalence of abnormal menisci was significantly higher in group II (69%) than in group I (38%, P < 0.05). Cartilage abnormalities were found in 21% of the triathletes with a higher prevalence in group II (31%) than in group I (8%, P < 0.05). Twenty-one percent (6/29) of the knees had bone contusions, with a higher prevalence in group II (31%) than in group I (8%, P < 0.05).
  
  
  CONCLUSIONS
  In general, the spectrum of abnormal MRI findings of the knee was no greater than age-related changes previously reported for other athletic populations and nonathletes. These results have important implications for the diagnostic use of MRI of the knee in this high-endurance, athletic population.
authors.affiliation: Institute for Magnetic Resonance Safety, Education, and Research, Los Angeles, California 90045, USA. frank.shellock@gte.net
authors.forename: Frank G
authors.initials: FG
authors.lastname: Shellock
authors.forename: W Douglas B
authors.initials: WD
authors.lastname: Hiller
authors.forename: George R
authors.initials: GR
authors.lastname: Ainge
authors.forename: David W
authors.initials: DW
authors.lastname: Brown
authors.forename: Laura
authors.initials: L
authors.lastname: Dierenfield
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013177:Sports