Background and purpose: Psychological factors including fear of pain, re-injury during movement (kinesiophbia) affect return-to-sport rates after anterior cruciate ligament (ACL) reconstructive surgery. Clinicians often encounter in the daily practice that athletes explain lack of self-confidence or psychological readiness during the sports activity. The Tampa Scale for Kinesiophobia (TSK) has been used to evaluate psychological outcomes in patients with ACL injuries in many countries and translated into Japanese version in 2013. However, no researchers validated its reliability, validity, and responsiveness of TSK for patients with ACL injury up to now. The purpose of this study was to evaluate the measurement properties of the Japanese version of the TSK (TSK-J) in patients with ACL injuries.
Study design: Cohort study (Diagnostic); Level of evidence, 2.
Methods: This prospective study was performed in the department of orthopaedic surgery at the university hospital of Juntendo from Sep 2016 and Apr 2017. Patients who diagnosed with ACL injury with or without reconstruction surgery completed several patient-reported outcome measures (PROMs) were included in this study. The COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) guidelines were used to evaluate reliability, validity, responsiveness, and interpretability of the TSK-J.
Results: 222 patients were included in this study. The TSK-J for ACL injured patients showed good internal consistency (Cronbach's alpha = 0.79) and excellent test-retest reliability (intra-class correlation coefficient, ICC2,1 = 0.90, 95% CI = 0.81 to 0.95). In addtion, the TSK-J was significantly but moderately correlated with the IKDC-SKF (r = - 0.49, P <0.001), VAS-Sports (r = - 0.48, P <0.001), and JACL-25 (r = 0.48, P <0.001). The effect size (ES) was small with the Cohen's d = - 0.2. The minimal important difference (MID) was - 1.3 points. No significant TSK-J score change was observed over 1-year after ACL reconstruction (r = - 0.12, P <0.001). There were no floor or ceiling effects.
Conclusions: Our study demonstrated that the Japanese version of TSK has good reliability. However, its low validity and responsiveness indicate that it may not the best way to assess psychological factors for patients with ACL injury.
Keywords: Anterior cruciate ligament (ACL); Tampa Scale for Kinesiophobia (TSK); The consensus-based standards for the selection of health status measurement INstruments (COSMIN); Validation study.