title: Bilateral differences in gait mechanics following total ankle replacement: a two year longitudinal study.
abstract: BACKGROUND
  Following total ankle replacement (TAR) patients demonstrate improvements in gait. The purpose of this study was to assess the changes in gait symmetry from a pre-operative assessment through two years following TAR.
  
  
  METHODS
  Seventy-eight patients who received a primary TAR and had no contralateral pain were examined. Three-dimensional joint mechanics and ground reaction forces were collected during seven walking trials pre-operatively, and 1 and 2-years post-operatively. Data was analyzed using a 2×3 repeated measures ANOVA to determine significant differences between limbs and across time points (α=0.05).
  
  
  RESULTS
  Walking speed improved from pre-operative to each post-operative time point (P<.001; ES=1.5). Peak dorsiflexion was not changed across time or between sides, however, the dorsiflexion angle at heel strike was increased on the nonsurgical side (P=0.049; ES=0.32). Peak plantar flexion moment (P<.001; ES=.80), stance (P<.001; ES=.29) and step time (P<.001; ES=.41) were improved from pre-op to 1year post-surgery on the surgical side. Step (P<.001; ES=1.2) and stride length (P<.001; ES=1.2) demonstrated improvements across all time points, while the weight acceptance (P<.001; ES=.27) and propulsion ground reaction forces (P<.001; ES=.22) showed improvements between pre-op and 1year post-op.
  
  
  CONCLUSIONS
  The results of the study indicate that the patients are able to walk faster and demonstrate an improvement in gait symmetry; however, this improvement does not return the patient to a symmetric walking pattern by 2years post-TAR.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3956, Durham, NC 27710, USA; Michael W. Krzyzewski Human Performance Research Laboratory, DUMC 3435, Duke University Medical Center, Durham, NC 27710, USA. Electronic address: robin.queen@duke.edu.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Queen
authors.affiliation: Michael W. Krzyzewski Human Performance Research Laboratory, DUMC 3435, Duke University Medical Center, Durham, NC 27710, USA; Division of Physical Therapy, Department of Community and Family Medicine, 2200 West Main St., Durham, NC 27705, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Butler
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3956, Durham, NC 27710, USA.
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Adams
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3956, Durham, NC 27710, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: DeOrio
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3956, Durham, NC 27710, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Easley
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3956, Durham, NC 27710, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Nunley
mesh_terms: D000704:Analysis of Variance; D000843:Ankle Joint / Q000503:physiopathology* / Q000601:surgery*; D001168:Arthritis / Q000628:therapy; D058737:Arthroplasty, Replacement, Ankle; D001696:Biomechanical Phenomena; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006801:Humans; D007595:Joint Prosthesis; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D011446:Prospective Studies; D016896:Treatment Outcome; D016138:Walking
keywords: Ankle arthritis; Gait symmetry; Total ankle replacement; Walking mechanics