title: MRI Quantification of the Impact of Ankle Position on Syndesmosis Anatomy.
abstract: BACKGROUND
  Despite the common occurrence of syndesmotic injuries in ankle trauma, the distal tibiofibular relationship remains poorly understood. The aim of this study was to evaluate the anatomical impact of ankle sagittal positioning on the tibiofibular relationship in intact ankles by using a validated magnetic resonance imaging (MRI)-based measurement system.
  
  
  METHODS
  In this radiologic study, 34 healthy volunteers underwent a series of ankle MRIs with the ankle stabilized in 3 positions: neutral position (NP), dorsiflexion (DF), and plantarflexion (PF). Using a previously validated measurement system, 6 fixed translational measurements and 2 fixed angles were recorded on each MRI and compared using paired t tests.
  
  
  RESULTS
  When comparing PF to DF, the anterior distance between the tibial incisura and the fibula varied from 2.5 mm to 3.9 mm ( P < .001), respectively. The middle distance between the tibial incisura and the fibula varied from 1.5 mm to 2.6 mm ( P < .001). Fibular angle varied from 8.7 degrees to 7.8 degrees of internal rotation ( P = .046), respectively. When comparing NP to DF, only the anterior distance was found to be significantly different, varying 0.4 mm ( P < .002).
  
  
  CONCLUSIONS
  Ankle dorsiflexion leads to an increase in external rotation and lateral translation of the fibula. These changes could be measured on MRI using a validated measurement system. Ankle motion did have an impact on the distal tibiofibular relationship and should be considered in studies pertaining to syndesmosis imaging.
  
  
  CONCLUSIONS
  This is the first in vivo study demonstrating the impact of sagittal ankle position on the distal tibiofibular relationship in an uninjured ankle. Our findings also support the practice of placing the ankle in dorsiflexion when fixing a disrupted syndesmosis.
  
  
  METHODS
  Level III, comparative study.
authors.affiliation: 1 CHU Ste-Justine, Montréal, QC, Canada.|2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: Marie-Lyne
authors.initials: ML
authors.lastname: Nault
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Marien
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: Jonah
authors.initials: J
authors.lastname: Hébert-Davies
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: G Yves
authors.initials: GY
authors.lastname: Laflamme
authors.affiliation: 4 McGill University, Department of Diagnostic Radiology, Montreal General Hospital, Montreal, QC, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Pelsser
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Rouleau
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: Nayla
authors.initials: N
authors.lastname: Gosselin-Papadopoulos
authors.affiliation: 2 Hôpital du Sacré-Cœur de Montréal, Montreal, QC, Canada.|3 Université de Montréal, Department of Surgery, Montreal, QC, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Leduc
mesh_terms: D000842:Ankle / Q000033:anatomy & histology*; D000843:Ankle Joint / Q000033:anatomy & histology*; D005360:Fibula / Q000033:anatomy & histology; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging; D012399:Rotation; D013977:Tibia / Q000033:anatomy & histology
keywords: MRI; dorsiflexion; neutral position; normal values; plantarflexion; syndesmosis