Psychometric properties of the 12-item Knee injury and Osteoarthritis Outcome Score (KOOS-12) Spanish version for people with knee osteoarthritis.

To evaluate the validity, reliability, and responsiveness to change of the 12-item Knee injury and Osteoarthritis Outcome Score (KOOS) Spanish version questionnaire. This study was based on a questionnaire validation design. A cross-sectional survey of 199 patients with knee osteoarthritis (KOA) and ten healthy controls was studied to evaluate the validity and reliability of KOOS-12.