title: Ankle stability in simulated lateral ankle ligament injuries.
abstract: BACKGROUND
  We performed a laboratory-based study of the ankle-hindfoot complex in normal cadaveric ankles with simulated lateral ankle ligament injuries, utilizing an ankle stability testing device. The ankle stability testing device distinguished between intact, injury to anterior talofibular ligament (ATFL) and combined injury to ATFL and calcaneofibular ligament (CFL).
  
  
  METHODS
  Ankles were tested in an ankle stability testing device, with a specified inversion torque applied through the range of sagittal plane motion, then internal rotation torque applied through the entire range of sagittal plane motion. Three-dimensional motion of the calcaneus and talus in relation to the tibia were determined with a magnetic tracking system. The specimens were tested in the intact condition, then after sectioning the ATFL, then the CFL.
  
  
  RESULTS
  Upon sectioning the ATFL, there was a significant increase in the internal rotation motion at the tibiotalar joint. Subsequent sectioning of the CFL did not significantly increase ankle-hindfoot internal rotation, but it did significantly increase the motion in inversion testing. This increase occurred primarily at the tibiotalar level.
  
  
  CONCLUSIONS
  The isolated ATFL injury was clearly distinguished from the intact condition by increased talar-tibial internal rotation, but not inversion. The more severe combined ATFL/CFL injury was distinguished from the ATFL injury condition with inversion torque.
  
  
  CONCLUSIONS
  Inversion torque may disclose combined ATFL/CFL injury, and internal rotation torque may be the key to distinguish isolated ATFL and combined ATFL/CFL injuries.
authors.affiliation: Orthopaedic Biomechanics Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Fujii
authors.forename: Harold B
authors.initials: HB
authors.lastname: Kitaoka
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Luo
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000503:physiopathology*; D002102:Cadaver; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000293:injuries* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012399:Rotation; D019415:Torque