Introduction: There are increasing numbers of older persons sustaining ankle fractures. This injury often results in a degree of functional limitation, particularly in older patients. There is currently limited research into factors associated with mobility outcomes.
Design: Observational cohort study.
Setting: Hospital Trauma Department, UK.
Participants: Persons aged 60 years or over who sustained an unstable ankle fracture with no established peripheral arterial disease pre-injury.
Methods: This study investigated the association between ankle-brachial pressure index (ABPI) and extended timed 'up and go' (TUG) measures. Associations between TUG outcomes and age, pre-morbid functional mobility (Olerud-Molander Ankle Score) and fracture severity (number of malleoli injured) were also explored.
Analysis: Complete cases (n=76; 84% of cohort) were entered into univariate and multivariate linear regression.
Results: No association was found between ABPI and TUG at 6 months in unadjusted and adjusted analyses. Pre-morbid functional mobility (B=-0.34, 95% confidence interval (CI) -0.45 to -0.23, p<0.001) and age (B=0.46, 95% CI 0.25-0.66, p<0.001) were associated with extended TUG values (r2=0.53, p<0.001). Fracture severity was not a significant independent predictor variable.
Conclusions: Peripheral vessel function and fracture severity may have a limited independent influence on mobility outcome after ankle fracture in those patients who do not have established pre-injury peripheral arterial disease. Age and pre-morbid mobility gave an indication of mobility outcome, but a substantial amount of variance remains unexplained. Limitations of this study, including missing data and potential residual confounding, indicate the need for caution in generalising these results. The study provides a basis on which to plan larger studies of the factors associated with mobility outcome after ankle fracture in older populations.
Copyright © 2012 Elsevier Ltd. All rights reserved.