title: Combined effect of toe out gait and high tibial osteotomy on knee adduction moment in patients with varus knee deformity.
abstract: BACKGROUND
  Gait adaptations, including toe out gait, have been proposed as treatments for knee osteoarthritis. The clinical application of toe out gait, however, is unclear. This study aims to identify the changes in Knee adduction moment in varus knee deformity assessing toe out gait as an alternative to high tibial osteotomy, and if any change in dynamic loading persists post operatively, when anatomical alignment is restored.
  
  
  METHODS
  Three-dimensional motion analysis was performed on 17 patients with medial compartment knee osteoarthritis and varus deformity prior to undergoing high tibial osteotomy, 13 patients were assessed post-operatively, and results compared to 13 healthy controls.
  
  
  RESULTS
  Pre-operatively, there was no significant difference between natural and toe out gait for measures of knee adduction moment. Post high tibial osteotomy, first (2.70 to 1.51% BW·h) and second peak (2.28 to 1.21% BW·h) knee adduction moment were significantly reduced, as was knee adduction angular impulse (1.00 to 0.52% BW·h·s), to a healthy level. Adopting toe out gait post-operatively reduced the second peak further to a level below that of healthy controls.
  
  
  CONCLUSIONS
  Increasing the foot progression angle from 20° (natural) to 30° in isolation did not significantly alter the knee adduction moment or angular impulse. This suggests that adopting a toe out gait, in isolation, in an already high natural foot progression angle, is not of benefit. Adopting toe out gait post-operatively, however, resulted in a further reduction in the second peak to below that of the healthy control cohort, however, this may increase lateral compartment load.
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK.
authors.forename: C
authors.initials: C
authors.lastname: Whelton
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK.
authors.forename: A
authors.initials: A
authors.lastname: Thomas
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff and Vale Orthopaedic Centre, University Hospital of Wales, Cardiff, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Elson
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK; Cardiff and Vale Orthopaedic Centre, University Hospital of Wales, Cardiff, UK.
authors.forename: A
authors.initials: A
authors.lastname: Metcalfe
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK.
authors.forename: S
authors.initials: S
authors.lastname: Forrest
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff and Vale Orthopaedic Centre, University Hospital of Wales, Cardiff, UK.
authors.forename: C
authors.initials: C
authors.lastname: Wilson
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK.
authors.forename: C
authors.initials: C
authors.lastname: Holt
authors.affiliation: Arthritis Research UK Biomechanics and Bioengineering Centre, Cardiff University, Cardiff, UK; Cardiff School of Engineering, Trevithick Building, Cardiff, UK. Electronic address: Whatlinggm@cardiff.ac.uk.
authors.forename: G
authors.initials: G
authors.lastname: Whatling
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D013996:Time and Motion Studies; D014034:Toes / Q000502:physiology