Translation and testing of measurement properties of the Swedish version of the IKDC subjective knee form.

Abstract

To translate to Swedish language and cross-culturally adapt the IKDC-SKF and to test the measurement properties of the Swedish version of IKDC-SKF in ACL-injured patients undergoing reconstruction surgery.The translation and cross-cultural adaption was performed according to guidelines. Seventy-six patients with an ACL injury filled out the IKDC-SKF and other questionnaires before ACL reconstruction and at 4, 6, and 12 months after surgery. A total of 203 patients from the Swedish ACL Registry participated at 8 months post-operative. Measurement properties were tested according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines.The Swedish IKDC-SKF had high internal consistency (Cronbach's alpha=0.90) and test-retest reliability (ICC2,1 =0.92, CI 95%: 0.81-0.97, P<.001). A single factor solution accounted for 46.1% of the variance in IKDC-SKF scores. Criterion validity was moderate to high. All ten predefined hypotheses for hypothesis testing were confirmed. The six hypotheses for responsiveness testing were confirmed. The effect size was 1.8, the standardized response mean was 1.9, the and minimal clinically important difference was 13.9 points.The Swedish version of the IKDC-SKF had good measurement properties and can be recommended for use in a population of ACL-deficient patients undergoing ACL reconstruction.