AAOS: First study to show similar gait outcomes for total ankle replacement vs arthrodesis

roomFirst study to show similar gait outcomes for total ankle replacement vs arthrodesis

Presentation Abstract
Session: 256-270-Foot and Ankle I
Location Room 3304
Presentation Number: Paper 258
Title: Gait and Balance in Total Ankle Arthroplasty versus Ankle Arthrodesis at 12 to 36 Months after Surgery
Classification: +Hindfoot (Foot/Ankle)
Keywords: Hindfoot / Ankle
Author(s): Brandon King, MD, Ypsilanti, Michigan
Todd A. Irwin, MD, Ann Arbor, Michigan
James Wrobel, DPM, Ann Arbor, Michigan
James R. Holmes, MD, Ann Arbor, Michigan
Markus Byron, BS, Brighton, Michigan
Abstract: INTRODUCTION: The evolution of total ankle arthroplasty with good intermediate term result now offers patients with ankle arthritis a treatment choice. Subjective patient self-scoring scales have shown ankle arthroplasty and arthrodesis to be similar, however little objective data exists. Our hypothesis was that patients who previously underwent total ankle arthroplasty would have significantly improved postoperative objective functional findings and similar self-scoring to ankle arthrodesis patients.
METHODS: Patients who had previously undergone ankle arthroplasty or arthrodesis one to three years ago were contacted and asked to participate. The surgery had been performed by one of two fellowship trained orthopaedic surgeons including either an open ankle arthrodesis with lag screws and/or plates and screws versus a total ankle arthroplasty using one manufacturer’s prosthesis. A novel, validated gait analyzer consisting of five wearable sensors for spatio-temporal and gait initiation was utilized. Data includes gait speed, stride length, double support time, and gait symmetry. Tandem and single leg stance with eyes open and eyes closed are evaluated individually. Functional outcomes were measured using the Ankle Osteoarthritis Scale (AOS), and a simple visual analog scale (VAS) was used to measure pain.
RESULTS: Twenty-one of the 26 patients identified agreed to undertake our evaluation, 12 arthroplasties and nine arthrodeses. The mean age was greater in the arthroplasty cohort, 69 vs. the arthrodesis cohort, 60.6 (p=0.11). The time since surgery between arthroplasty and arthodesis was statistically significantly different (p=0.008), 17.9 months vs 26.8 months, respectively. Gait characteristics between the two cohorts were surprisingly similar and specifics can be seen in table 1. All gait characteristics were not statistically significant between the cohorts. Balance characteristics were calculated as centimeters sway from midline during a 15 second tandem and single leg stance with eyes open and then closed. The only statistically significant finding (p=0.05) was open-eye tandem Romberg testing in the anterior-posterior plane with the arthrodesis cohort scoring better than the arthoplasty cohort. In both scales used for pain and disability lower numbers indicate a better outcome. Functional outcomes using the AOS scale (table 2) showed a trend toward better outcomes in the arthroplasty cohort, though the numbers did not reach significance.
DISCUSSION AND CONCLUSION: Our data lends support to previous studies which have shown pain and disability to be similar after surgery in both arthroplasty and arthrodesis cohorts. This is, however, the first study to our knowledge showing gait to be similar in arthrodesis and arthroplasty patients and only study of its kind evaluating one manufacturer’s prosthesis. We also demonstrate the utility of a portable, wireless gait and balance system that can be used for clinical and research purpose.

Gait Characteristics
Arthroplasty Arthrodesis p value
stride length 1.09 m 1.24 m 0.27
velocity 0.95 m/s 1.04 m/s 0.93
cadence 95.3 98.3 0.37
operative side single support 32.9% 37.5% 0.13
double support 27.8% 27.8% 0.29
pain and disability
Arthroplasty Arthrodesis p value
VAS 1.5 3.1 0.20
AOS total 41.9 56.8 0.46
AOS pain 16.2 20.1 0.75
AOS disability 41.9 56.8 0.31
Uncategorized