The multiligament quality of life questionnaire: development and evaluation of test-retest reliability and validity in patients with multiligament knee injuries

Background: Existing knee joint-specific outcome questionnaires lack content pertinent to patients with multiligament knee injuries. Purpose: To develop and test the reliability and validity of a novel disease-specific quality of life questionnaire for patients with multiligament knee injuries. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Participants in this study included patients with multiligament knee injuries and clinician experts. Inclusion criteria were (1) patients with multiligament knee injury (age, 18-60 years), (2) =6 months after injury, and (3) operative or nonoperative treatment. Exclusion criteria were (1) preexisting osteoarthritis or inflammatory arthritis and (2) intracerebral/spinal cord injury. In phase I of the study, 85 eligible patients were mailed a questionnaire composed of 132 items from 11 existing knee questionnaires. Items were rated with regard to importance and frequency on a 5-point Likert scale. Criteria for inclusion in the first draft of the Multiligament Quality of Life (MLQOL) questionnaire included mean importance rating =3.5 and frequency