Reliability, validity, and responsiveness of the IKDC score for meniscus injuries of the knee.
OBJECTIVE
The purpose of this study was to determine the psychometric properties of the International Knee Documentation Committee (IKDC) score for meniscus injuries of the knee.


METHODS
Test-retest reliability, content validity, construct validity, and responsiveness to change were determined for the IKDC score. Knees were excluded if they had ligament pathology or a chondral defect greater than Outerbridge grade 2. All patients had meniscus pathology requiring treatment. The study comprised 4 subsets of patients. Group A consisted of 31 patients who completed an IKDC form at least 2 years after surgery for meniscus pathology and were then retested within 4 weeks of the primary questionnaire. Group B contained 264 patients with preoperative IKDC scores that were used for construct and content validity. Group C contained 50 patients who had a preoperative IKDC score and completed a short form 12 survey. Group D contained 100 patients with preoperative and postoperative IKDC scores used to measure responsiveness.


RESULTS
The overall IKDC score showed acceptable test-retest reliability with an interclass correlation of 0.95. There were acceptable floor and ceiling effects. All constructs tested showed significant differences. These included lower IKDC score with the following: lower activity level, difficulty with activities of daily living, difficulty with sports, abnormal knee function, and complex/degenerative meniscus tears. Responsiveness to change showed a large effect size (2.11) and a large response mean (1.5) for the overall score. The SE of the measurement was 3.19, and the minimum detectable change was 8.8 points.


CONCLUSIONS
The overall IKDC score showed overall acceptable psychometric performance for outcome measures of meniscus injuries of the knee.


METHODS
Level III, testing of previously developed diagnostic criteria in nonconsecutive patients.
Crawford
Kevin
K
Lubbock Sports Medicine Associates, Lubbock, Texas, USA.
Briggs
Karen K
KK
Rodkey
William G
WG
Steadman
J Richard
JR
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D007717:Knee / Q000503:physiopathology; D022125:Lacerations / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011594:Psychometrics / Q000379:methods; D015203:Reproducibility of Results; D013177:Sports; D011795:Surveys and Questionnaires; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome; D014947:Wounds and Injuries / Q000503:physiopathology