Archives of Orthopaedic and Trauma Surgery

, Volume 134, Issue 7, pp 897–901 | Cite as

Translation and validation of the German version of the foot and ankle outcome score

  • C. J. A. van Bergen
  • I. N. Sierevelt
  • P. Hoogervorst
  • H. Waizy
  • C. N. van Dijk
  • C. Becher
Orthopaedic Surgery



Outcome assessment is critical in evaluating the efficacy of orthopaedic procedures. The Foot and Ankle Outcome Score (FAOS) is a 42-item questionnaire divided into five subscales, which has been validated in several languages. Germany has no validated outcome score for general foot and ankle pathology. The aim of this study was to develop a German version of the FAOS and to investigate its psychometric properties.

Materials and methods

Forward and backward translation was executed according to official guidelines. The final version of the FAOS was investigated in 150 patients with various foot and ankle disorders. All patients completed the FAOS, Short Form-36, numeric rating scales for pain and disability, and the Hannover questionnaire. The FAOS was re-administered after 1 week. Test–retest reliability, internal consistency, minimal detectable change, construct validity, and floor and ceiling effects were analyzed.


Test–retest reliability and internal consistency of each subscale were excellent (intraclass correlation coefficient, 0.88–0.95; Cronbach’s α, 0.94–0.98). The minimal detectable changes of each subscale were 17.1–20.8 at the individual level and 2.0–2.4 at group level. There were moderate to strong correlations between FAOS subscales and physical outcomes and low to moderate correlations between FAOS subscales and mental outcomes. Floor and ceiling effects were not present.


The German version of the FAOS is a reliable and valid instrument for use in foot and ankle patients.


FAOS Patient reported outcome measures Psychometrics Questionnaire Translation Validation 

Supplementary material

402_2014_1994_MOESM1_ESM.doc (61 kb)
Final translated version of the German Foot and Ankle Outcome Score. (DOC 61 kb)


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • C. J. A. van Bergen
    • 1
  • I. N. Sierevelt
    • 1
  • P. Hoogervorst
    • 2
  • H. Waizy
    • 3
  • C. N. van Dijk
    • 1
  • C. Becher
    • 4
  1. 1.Department of Orthopaedic Surgery, Orthopaedic Research Center Amsterdam, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
  2. 2.Department of Orthopaedic SurgeryRadboud UniversityNijmegenThe Netherlands
  3. 3.Foot and Ankle Clinic, Hessing FoundationAugsburgGermany
  4. 4.Department of Orthopaedic SurgeryHannover Medical SchoolHannoverGermany

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