title: Does alignment in the hindfoot radiograph influence dynamic foot-floor pressures in ankle and tibiotalocalcaneal fusion?
abstract: BACKGROUND
  The Saltzman-el-Khoury hindfoot alignment view (HAV) is considered the gold standard for assessing the axis from hindfoot to tibia. However, it is unclear whether radiographic alignment influences dynamic load distribution during gait.
  
  
  OBJECTIVE
  We evaluated varus-valgus alignment by the HAV and its influence on dynamic load distribution in ankle and tibiotalocalcaneal (TTC) arthrodesis.
  
  
  METHODS
  We clinically assessed 98 patients (ankle, 56; TTC, 42) with SF-36 and American Orthopaedic Foot and Ankle Society (AOFAS) scores, visual hindfoot alignment, HAV angle, and dynamic pedobarography using a five-step method. For comparison, 70 normal feet were evaluated. Minimum followup was 2 years (average, 4.11 years; range, 2-6 years).
  
  
  RESULTS
  The mean HAV angle was -0.8° ± 7.8° for ankle and -1.2° ± 6.9° for TTC arthrodesis. The HAV angle correlated with pedobarographic load distribution (r = 0.35-0.53). Radiographic alignment did not influence SF-36 or AOFAS scores; however, load distribution correlated to qualities of these scores. Visual alignment only predicted the corresponding HAV angle in 48%. To reproduce the dynamic load of healthy subjects, HAV angles of 5° to 10° valgus were needed.
  
  
  CONCLUSIONS
  Visual positioning is inadequate to determine intraoperative positioning and resulted in a varus position with a relatively large SD. The HAV should be used to assess the hindfoot alignment correctly. HAV angles of 5° to 10° valgus are needed to reproduce a physiologic gait pattern.
authors.affiliation: Department of Orthopaedics, University of Calgary, Calgary, Canada. mail@arnofrigg.com
authors.forename: Arno
authors.initials: A
authors.lastname: Frigg
authors.forename: Benno
authors.initials: B
authors.lastname: Nigg
authors.forename: Elysia
authors.initials: E
authors.lastname: Davis
authors.forename: Beth
authors.initials: B
authors.lastname: Pederson
authors.forename: V
authors.initials: V
authors.lastname: Valderrabano
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D001174:Arthrodesis; D002111:Calcaneus / Q000000981:diagnostic imaging / Q000601:surgery*; D002170:Canada; D016022:Case-Control Studies; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D011859:Radiography; D020127:Recovery of Function; D012189:Retrospective Studies; D013628:Talus / Q000000981:diagnostic imaging / Q000601:surgery*; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome