title: Assessment of lateral hindfoot pain in acquired flatfoot deformity using weightbearing multiplanar imaging.
abstract: BACKGROUND
  The etiology of lateral hindfoot pain in flatfoot deformity can be difficult to assess on plain radiographs. We hypothesized that multiplanar measurements obtained in a fully upright, weightbearing position would reliably demonstrate an increase in lateral hindfoot arthrosis and/or impingement in a cohort of flatfoot patients with lateral hindfoot pain compared to a cohort without pain.
  
  
  METHODS
  Ten consecutive patients with flexible flatfoot deformity and lateral hindfoot pain (mean age, 55.5 +/- 13.9) were compared to 10 consecutive patients with flexible deformity but no pain (mean age, 61.0 +/- 8.6). Conventional radiographs and weightbearing multiplanar images were performed on all patients before surgical reconstruction. Flatfoot, hindfoot impingement, and arthrosis parameters were interpreted in a blinded fashion by two musculoskeletal radiologists. Interrater reliability was determined with intraclass correlation coefficients (ICC). All parameters were compared between groups with a Wilcoxon rank sum test (p < 0.05).
  
  
  RESULTS
  A significant increase in posterior facet subtalar arthrosis (p = 0.006) and combined anterior and posterior facet subtalar arthrosis (p = 0.022) was evident in the pain group. Calcaneofibular impingement and calcaneocuboid arthritis were increased in the pain group, but did not reach significance (p = 0.057 and p = 0.067 respectively). The multiplanar imaging parameters demonstrated good (ICC = 0.60 to 0.73) to excellent (ICC >or= 0.74) reliability for most impingement and arthrosis parameters and for many of the standard flatfoot parameters.
  
  
  CONCLUSIONS
  The results indicate that weightbearing, multiplanar imaging provides a reliable means of assessing lateral pain in patients with flexible flatfoot deformity.
authors.affiliation: Department of Foot and Ankle Surgery, The Hospital for Special Surgery, New York, NY 10021, USA. elliss@hss.edu
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Ellis
authors.forename: Timothy
authors.initials: T
authors.lastname: Deyer
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Williams
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Yu
authors.forename: Scott
authors.initials: S
authors.lastname: Lehto
authors.forename: Alex
authors.initials: A
authors.lastname: Maderazo
authors.forename: Helene
authors.initials: H
authors.lastname: Pavlov
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Deland
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005413:Flatfoot / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005531:Foot Deformities, Acquired / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D033023:Foot Joints / Q000000981:diagnostic imaging / Q000503:physiopathology; D006365:Heel; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010146:Pain / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed; D016474:Weight-Bearing; D055815:Young Adult