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Updated: Jun 6, 2026
Treatment of Ankle Osteoarthritis with Total Ankle Replacement Through a Lateral Transfibular Approach
Published on: January 24, 2018
Dimensionality of measures for severe unilateral ankle arthritis
Chad Cook1, Robin M Queen, Emily J Slaven
1Division of Physical Therapy, Walsh University, North Canton, OH 44720, USA. ccook@walsh.edu
Objective:
To analyze the dimensionality of 2 self-report outcome measures (Foot/Ankle Disability Index [FADI] and Short-Form [SF]-36), 3 biomechanical measures (stance and step symmetry measures, gait speed, and step width), 2 physical-performance measures (timed get-up and go [TUG] and 4-square step test [4SST]), and 1 clinician-report outcome measure (American Orthopaedic Foot and Ankle Society [AOFAS] Hindfoot Scale) in a patient population with unilateral ankle arthritis. These measures captured the following functions: mobility and speed, pain and its relationship to function, social integration, and symmetry and efficiency of gait.
Design:
Case series design.
Setting:
Biomechanical research laboratory adjacent to a busy orthopedic clinical practice.
Patients:
Seventy-nine consecutive patients with unilateral traumatic arthritis who were candidates for a total ankle replacement.
Methods:
An exploratory factor analysis with oblimin rotation was performed to determine the dimensions of the physical performance, biomechanical, self-report, and clinician-report measures.
Main Outcome Measurements:
Outcomes measures included the SF-36 and pertinent subscales, gait speed, the 4SST, the TUG, the FADI, the AOFAS Hindfoot Scale, and biomechanical measures of step width, step symmetry, and stance symmetry.
Results:
Four distinct dimensions were captured during factor analysis. Factor 1 included the TUG, gait speed, the 4SST, and step width; factor 2 included the FADI, the SF-36 bodily pain score, and the SF-36 physical function score; factor 3 included the biomechanical scores of stance symmetry ratio and the step symmetry ratio; and factor 4 included SF-36 social functioning and the AOFAS Hindfoot Scale.
Conclusions:
Findings suggest that various outcome measures for the ankle capture different dimensions and should be considered when evaluating the presence of disability or long-term change in outcome.
