Background With the increasing prevalence of knee osteoarthritis (KOA) today1, it is imperative to use valid and reliable instruments to evaluate the effectiveness of interventions and to understand the pathology's impact on individuals.
Objectives The aim of this study was to review the measurement properties of instruments used by physiotherapists to evaluate people with kOA. This review covers the “anatomical structure” and “body function” components of the International Classification of Functioning, Disability and Health (ICF) Core Set for KOA2.
Methods Systematic searches were conducted on various databases until June 2011. Articles were sorted by two independent investigators based on the following criteria: 1) publication in French or English; 2) studies on measurement properties; and 3) KOA population. Disagreements were resolved through discussion and if necessary, by a third reviewer. Both investigators used a scale developed by Brink et al.3 for quality assessment and then, proceeded to data extraction. A critical review of available evidence was developed.
Results Anatomical Structure: the inclinometer method appears to be a valid alternative to the mechanical axis measured on radiograph (r =0.80). Body function categories: Pain: Most studies involved the validation of algo-functional questionnaires and showed excellent reliability. The Visual Analog Scale (VAS pain) and the Intermittent and Constant Osteoarthritis Pain (ICOAP) had good to excellent validity and reliability scores (r =0.89-0.96). Joint function: The capsular pattern of Cyriax did not discriminate KOA patients from healthy controls. Active knee repositioning using prediction equations demonstrated good validity (r=0.84-0.90) and moderate reliability (ICC =0.46-0.47) for joint proprioception. The Pivot Shift Test did not prove to be a valid measure of antero-lateral stability in KOA. Muscle function: isometric and isokinetic muscular testing revealed good reliability but high measurement errors (30%>36.2%); hand-held dynamometry was more valid than manual muscle testing (which overestimates muscle strength; Kendall correlation coefficient =0.24) and prediction equations were a valid replacement for the 1-RM procedure (ICC 0.96-0.99). ESE: The Joint-Specific Multidimensional Assessment of Pain (J-MAP) offered a satisfactory measure of emotional impact of pain (ICC =0.49-0.64).
Conclusions Current literature shows much interest in transcultural validation of algo-functional questionnaires. However, validation of the instruments in the other categories is lacking. Further high-quality studies are needed to adequately choose a body function instrument for this population.
Alliance Canadienne de l'Arthrite (2013). The Impact of Arthritis in Canada: Today and Over the Next 30 Years. Available from: http://www.arthritisalliance.ca/docs/20111022_2200_impact_of_arthritis.pdf
Feng Xie et al., Validation of the Comprehensive ICF Core Set for Osteoarthritis (OA) in patients with knee OA: a Singaporean perspective. J Rheumatol 2007;34;2301-2307.
Brink, Y. et Louw, Q. A. (2012). Clinical instruments: reliability and validity critical appraisal. Journal of Evaluation in Clinical Practice, 18(6), pp. 1126-1132.
Acknowledgements Pre Nathaly Gaudreault received a grant from the REPAR-IRSST partnership program to carry out this study
Disclosure of Interest None declared