GAIT ANALYSIS AND FUNCTIONAL OUTCOMES OF PATIENTS WITH AN ISOLATED ANKLE ARTHRODESIS FOR POST-TRAUMATIC OR IDIOPATHIC ANKLE ARTHRITIS.

Abstract

Ankle arthrodesis for isolated ankle arthritis has a high patient satisfaction level; however, gait analysis and functional outcome measurements demonstrate substantial disability. The high patient satisfaction may reflect the extent of disability present prior to the intervention.

This study demonstrates that the presence of subtalar or talonavicular arthritis and/or limited motion is a negative predictor for a satisfactory outcome. The risk of developing arthritis of these joints increases with time and therefore the patient can expect a deterioration of their initial result. Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve motion should continue to be explored.

The purpose of this study was to utilize gait analysis and validated outcome measures to assess the results of an ankle arthrodesis and compare these results to a healthy age – sex matched control group.

Isolated Ankle arthrodesis has a high patient satisfaction rate; however, gait analysis and functional outcome scores demonstrate a significant difference when compared to controls. The presence of limited subtalar and midfoot motion and/or arthritis correlates with a poor clinical result.

This study will help the clinician predict outcomes and better educate patients as to the expected results following ankle arthrodesis.

Twenty-six patients with an isolated ankle arthrodesis underwent gait analysis and functional outcome assessment using AOFAS ankle-hindfoot scale, MODEMS (includes SF-36) and Ankle Osteoarthritis Scale (AOS). A radiographic analysis was preformed. Mean follow-up was 3.7 years. Results were compared to a group of twenty-six controls.

Seventy-seven percent were satisfied and eighty-eight percent would recommend it to a friend. These perceived outcomes did not correlate well with their average Functional Outcome scores and gait analysis. The AOFAS score rated 46% as excellent or good. The MODEMS identified significant differences in Physical Function, Role-Physical and Physical Composite means when compared to controls. The AOS identified significant differences in Pain and Disability means. Gait analysis demonstrated significant differences in stride length, cadence, hip flexion, hindfoot flexion, hindfoot inversion and midfoot flexion. Decreased hindfoot and midfoot motion correlated with poorer outcome scores. Poor radiographic scores correlated with decreased hindfoot/midfoot motion and poorer clinical outcomes.

Ankle arthrodesis should be considered a salvage procedure. Viable alternatives that preserve ankle motion should continue to be explored.