title: Assessment of female ballet dancers' ankles in the en pointe position using high field strength magnetic resonance imaging.
abstract: BACKGROUND
  The en pointe position of the ankle in ballet is extreme. Previously, magnetic resonance imaging (MRI) of ballet dancers' ankles en pointe was confined to a low field, open MR device.
  
  
  OBJECTIVE
  To develop a reproducible ankle MRI protocol for ballet dancers en pointe and to assess the positions of the key structures in the dancers ankles.
  
  
  METHODS
  Six female ballet dancers participated; each was randomly assigned to stand en pointe while one of her feet and ankles was splinted with wooden rods affixed with straps or to begin with the ankle in neutral position. She lay in an MR scanner with the ankle inside a knee coil for en pointe imaging and inside an ankle/foot coil for neutral position imaging. Proton density weighted images with and without fat suppression and 3D water excitation gradient recalled echo images were obtained en pointe and in neutral position in sagittal, axial, and coronal planes. We compared the bones, cartilage, and soft tissues within and between positions.
  
  
  RESULTS
  No difficulties using the protocol were encountered. En pointe the posterior articular surface of the tibial plafond was incongruent with the talar dome and rested on the posterior talus. The posterior edge of the plafond impinged Kager's fat pad. All participants exhibited one or more small ganglion cysts about the ankle and proximal foot, as well as fluid accumulation in the flexor and fibularis tendon sheaths.
  
  
  CONCLUSIONS
  Our MRI protocol allows assessment of female ballet dancers' ankles in the extreme plantar flexion position in which the dancers perform. We consistently noted incongruence of the talocrural joint and convergence of the tibia, talus, and calcaneus posteriorly. This protocol may be useful for clinicians who evaluate dancers.
authors.affiliation: School of Applied Health Sciences, Ohio University, Athens, Ohio, USA jeff.russell@ohio.edu.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Russell
authors.affiliation: Department of Radiological Sciences, School of Medicine, University of California, Irvine, California, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshioka
mesh_terms: D000843:Ankle Joint / Q000000981:diagnostic imaging*; D003615:Dancing; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Dance; ankle; ballet; magnetic resonance imaging (MRI); pointe; talocrural