Abstract
Purpose
Identifying optimal treatment strategies for inpatients with traumatic foot and ankle injuries has been hampered by a wide variety of outcome measures with unproven reliability and validity. It remains plausible that the choice of functional outcome measures may influence measurement of treatment effects. This prospective observational study aims to measure the correlation and agreement across six functional outcome measures in patients with traumatic foot and ankle injuries.
Methods
Patients 18 years of age or older with a traumatic foot or ankle injury completed the Short Form-12 (SF-12), Short Musculoskeletal Functional Assessment (SMFA), Foot Function Index (FFI), Foot and Ankle Ability Measure (FAAM), American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle Questionnaire and American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale at a single follow-up visit. Raw scores were calculated and transformed to a functional level of excellent, very good, good, fair or poor. Pearson correlation co-efficients providing measures of correlation and agreement between functional levels were assessed.
Results
Fifty-two patients were enrolled at a mean follow-up of 15.5 months. Moderate to strong correlations were found for most pair-wise comparisons of raw scores and functional levels (?=0.43-0.92, p< 0.002). The strongest correlations were found between the SMFA, FFI, FAAM and AAOS Foot and Ankle Questionnaire. Despite significant correlation between scores, considerable disagreement between functional levels was observed. None of the 52 subjects attained the same functional level on all 6 outcome measures.
Conclusion
High correlations between scores and functional level suggest it is unnecessary to use more than one outcome measure when examining functional outcome in patients with foot and ankle trauma. However, inconsistencies between functional levels attained with the different instruments suggest a need for further validation and scrutiny.
