Foot & Ankle International - 2017 FAI Supplement - 33S

Foot & Ankle International, 38(S1)
DOI: 10.1177/1071100717S00029
©The Author(s) 2017

The Effect of Ankle Arthrodesis on the
Biomechanical Function of the Foot:
A Prospective, Three-Dimensional,
Multi-Segment Gait Analysis With
Clinical Correlation
Michal Kozanek, MD, PhD, James Brodsky, MD,
Justin Kane, MD
Category: Ankle, Ankle Arthritis, Basic Sciences/Biologics,
Hindfoot
Keywords: ankle arthritis, gait analysis
Introduction/Purpose: Several studies on the effect on gait
of total ankle arthroplasty (TAA) have demonstrated significant functional improvement post-operatively, compared to
the patients' preoperative function. While there are many
post-operative studies showing abnormalities of gait in
patients who have had ankle arthrodesis, there are very limited published data in ankle fusion which compare post-operative gait to the patients' own preoperative function.
Moreover, there are no published correlation of those gait
changes with patient reported outcomes.
Methods: Twenty-six consecutive ankle arthrodesis patients
were prospectively studied, with pre- and post-operative
three-dimensional gait analysis. Kinematic data were collected at 100 Hz with a twelve-camera digital Vicon motion

AOFAS Annual Meeting 2017

capture system, and two OR6-5 AMTI force plates. Patients
walked barefoot at a self-selected speed over a 10-meter
walkway. A minimum 20 gait cycles were used for averaging
and statistical analysis for temporal-spatial and kinematic
parameters and a minimum of five force plate readings for
kinetic parameters. Gait parameters were collected for both
operated and unaffected limbs (i.e. control). Demographic
data were compiled. Prospectively collected patient-reported
outcomes included SF-36, VAS, AOFAS scores, which were
repeated annually postoperatively.
Results: Mean age was 56 (19 - 80) years, BMI 29.7 (18.6 45.6), and follow-up 21.9 (12 - 69) months. There were multiple objective parameters of gait which showed statistically
significant functional improvements compared to preoperative performance.
Temporal-spatial: Improvements were detected in walking
speed, step length and cadence; single and double limb support time. Kinematic parameters: Increase in maximum plantarflexion, decrease in maximum dorsiflexion, but total
sagittal range of motion was not diminished, and slightly
increased (mean 1.8 degrees). The preservation of total sagittal motion after arthrodesis suggested either precise postoperative compensation by the hindfoot, or that most of the
preoperative motion was already occurring in the surrounding hindfoot joints. Kinetic parameters: Improvement in
ankle moment and hip power were detected.
Patient reported outcomes (table)
Conclusion: Ankle arthrodesis improves gait in end-stage
arthritis, as demonstrated by statistically significant improvements in multiple, objective parameters. Moreover, the
increase in sagittal plane motion of the hindfoot, presumed in
the literature to be compensatory to the arthrodesis, was shown

33S

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