title: Intertester reliability of sonography in patellar tendinopathy.
abstract: OBJECTIVE
  Intertester reliability is imperative during the sonographic assessment of patellar tendinopathy because hypoechoic areas can change over time, and repeated examination may involve multiple examiners. Given that, to our knowledge, it has not been reported in the literature, the objective of this study was to investigate the intertester reliability of sonography for the detection and measurement of hypoechoic areas associated with patellar tendinopathy.
  
  
  METHODS
  The study cohort comprised 8 patients with clinically diagnosed patellar tendinopathy and 4 patients with bilateral asymptomatic patellar tendons. Two equally experienced musculoskeletal radiologists imaged both patellar tendons from each patient (n = 24). All 24 tendons were assessed on the same day with the use of identical sonography machines.
  
  
  RESULTS
  The radiologists had 100% chance-corrected agreement for detecting 12 normal (hypoechoic free) and 12 abnormal (hypoechoic) tendons. All measurement data were normally distributed (P > .05), and a range of hypoechoic area sizes was evident. No statistically significant differences were found for the measurements of hypoechoic area, axial plane height and width, and sagittal plane height (P > .05). In addition, these measurements were equally highly correlated (Pearson r > 0.87; P < .01).
  
  
  CONCLUSIONS
  The results reported in this study suggest that the intertester reliability of sonography for the assessment of patellar tendinopathy is high. Although these results are encouraging, a small sample was analyzed, and this increases the probability of type II measurement error. Larger studies are therefore required to confirm these findings. High intertester reliability indicates that multiple experienced radiologists can reliably assess the same tendon and provides researchers with a necessary foundation for furthering research in tendon rehabilitation.
authors.affiliation: Musculoskeletal Research Centre, School of Physiotherapy, La Trobe University, Bundoora, Melbourne, Victoria, Australia. jeni@deakin.edu.au
authors.forename: Jennifer
authors.initials: J
authors.lastname: Black
authors.forename: Jill
authors.initials: J
authors.lastname: Cook
authors.forename: Z Stephen
authors.initials: ZS
authors.lastname: Kiss
authors.forename: Michael
authors.initials: M
authors.lastname: Smith
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D010329:Patella / Q000000981:diagnostic imaging / Q000293:injuries*; D015203:Reproducibility of Results; D013708:Tendon Injuries / Q000000981:diagnostic imaging*; D014463:Ultrasonography