title: The ability of ultrasonography, magnetic resonance imaging and bone mineral densitometry to predict the strength of human Achilles' tendons.
abstract: OBJECTIVE
  To assess the value of ultrasonography (US), magnetic resonance imaging (MRI), and bone mineral densitometry (BMD) in evaluating human Achilles' tendon strength.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  Tertiary care hospital.
  
  
  METHODS
  Ninety-eight Achilles' tendons from 49 consecutive cadavers (26 men and 23 women with a mean age of 66.6 years) undergoing hospital autopsy were assessed.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Tendon dimensions on US and MRI, and T1-weighted optical density were measured. Areas of hypodensity, hyperdensity, calcification, and heterogeneity were identified on US. The BMD of each calcaneus was recorded. The tendons were mechanically tested to determine peak load at failure.
  
  
  RESULTS
  Sixteen patients (32.7%, 27 tendons) had abnormalities in 1 or both tendons on US and/or MRI (17 on US, 17 on MRI). Fifty-seven tendons (58%) ruptured in their midsubstance, at an average peak load of 4722+/-990N. Tendons with and without abnormalities on imaging had similar strengths (P>.05). Calcaneal BMD correlated weakly with peak load at failure (r=.21, P<.05).
  
  
  CONCLUSIONS
  The prevalence of Achilles' tendons abnormalities on US or MRI was 32.7% in our study group. Abnormalities on clinical imaging (US or MRI) were not predictive of the load at failure. Therefore, tendons with imaging abnormalities are not necessarily weaker, and one cannot predict the likelihood of rupture based on imaging results. Further, higher-powered studies could explore the ability of BMD to detect minimal clinically important differences and to predict Achilles' tendon weakness.
authors.affiliation: Bone and Joint Research Laboratory, University of Ottawa, Ottawa, ON, Canada. dldevitt@gmail.com
authors.forename: Deanna
authors.initials: D
authors.lastname: Devitt
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Koike
authors.forename: Geoffrey P
authors.initials: GP
authors.lastname: Doherty
authors.forename: Nanthan
authors.initials: N
authors.lastname: Ramachandran
authors.forename: Laurent
authors.initials: L
authors.lastname: Dinh
authors.forename: Hans K
authors.initials: HK
authors.lastname: Uhthoff
authors.forename: Martin
authors.initials: M
authors.lastname: Lecompte
authors.forename: Guy
authors.initials: G
authors.lastname: Trudel
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000125:Achilles Tendon / Q000503:physiopathology*; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D003430:Cross-Sectional Studies; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011336:Probability; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D013708:Tendon Injuries / Q000175:diagnosis / Q000209:etiology; D013718:Tensile Strength / Q000502:physiology*; D018608:Ultrasonography, Doppler / Q000379:methods