Validity and internal consistency of the American Orthopaedic Foot and Ankle Society Midfoot Scale in patients with Lisfranc injury

Ville T Ponkilainen; Mikko Uimonen; Jussi P Repo; Ville M Mattila; Heidi H Haapasalo

doi:10.1016/j.fas.2019.06.005

Validity and internal consistency of the American Orthopaedic Foot and Ankle Society Midfoot Scale in patients with Lisfranc injury

Foot Ankle Surg. 2020 Jul;26(5):523-529. doi: 10.1016/j.fas.2019.06.005. Epub 2019 Jun 21.

Authors

Ville T Ponkilainen¹, Mikko Uimonen², Jussi P Repo³, Ville M Mattila⁴, Heidi H Haapasalo⁵

Affiliations

¹ University of Tampere, School of Medicine, Tampere 33520, Finland; Department of Orthopaedics and Traumatology, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Teiskontie 35, Tampere, PL2000, 33521, Finland. Electronic address: ponkilainen.ville.t@student.uta.fi.
² University of Tampere, School of Medicine, Tampere 33520, Finland.
³ Department of Surgery, Central Finland Central Hospital, Jyväskylä, Finland.
⁴ University of Tampere, School of Medicine, Tampere 33520, Finland; Department of Orthopaedics and Traumatology, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Teiskontie 35, Tampere, PL2000, 33521, Finland; COXA Hospital for Joint Replacement, Biokatu 6, Tampere 33520, Finland.
⁵ Department of Orthopaedics and Traumatology, University of Tampere, Faculty of Medicine and Life Sciences and Tampere University Hospital, Teiskontie 35, Tampere, PL2000, 33521, Finland.

PMID: 31255577
DOI: 10.1016/j.fas.2019.06.005

Abstract

Background: The American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Scale is an extensively used outcome measure instrument for evaluating outcomes after foot and ankle surgery or trauma.

Methods: In total, 117 patients with Lisfranc injury completed the AOFAS Midfoot Scale and the Visual Analogue Scale Foot and Ankle (VAS-FA) instruments. Internal consistency (correlation between different items), floor and ceiling values, convergent validity, item threshold distribution, and the coverage (item difficulty) of the AOFAS Midfoot scale were tested.

Results: AOFAS Midfoot Scale had high convergent validity and acceptable internal consistency (Cronbach's alpha >0.70). The ceiling effect was confirmed. The person-item distribution indicated that the scale had a lack of coverage and targeting in our sample.

Conclusions: Our data suggests that the AOFAS Midfoot Scale has acceptable validity and internal consistency. However, due to the lack of coverage and targeting, it should not be the primary outcome measure to be used to evaluate the outcomes after Lisfranc injury in the future studies.

Keywords: AOFAS; Lisfranc; Measure; Midfoot; Outcome; VAS-FA.

Publication types

Multicenter Study

MeSH terms

Adult
Ankle Injuries / diagnosis*
Female
Humans
Male
Orthopedics*
Pain Measurement / methods*
Reproducibility of Results
Societies, Medical*
Surveys and Questionnaires
Tarsal Joints / injuries*
United States