Correlation of a Single Assessment Numeric Evaluation (SANE) Rating With Modified Cincinnati Knee Rating System and IKDC Subjective Total Scores for Patients After ACL Reconstruction or Knee Arthroscopy

Abstract

Background: Limited studies exist regarding how well a single assessment numeric evaluation (SANE) rating correlates with validated knee surveys. Purpose: To determine whether a SANE rating correlates positively with the International Knee Documentation Committee (IKDC) and the modified Cincinnati Knee Rating System (CKRS) total scores after knee surgery. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: Patients undergoing either anterior cruciate ligament (ACL) reconstruction or knee arthroscopy were prospectively given subjective evaluations yearly after surgery between January 2000 and June 2011. Subjective evaluations were obtained using modified CKRS and IKDC subjective knee surveys and a SANE rating. Interclass correlation coefficient was used to determine the correlation of the SANE rating to the survey total scores. Bland-Altman method was used to access precision and limits of agreement between scores. In addition, the data were analyzed according to sex and age categories (<18, 18-24, 25-40, >40 years). Results: A total of 11,939 surveys were collected from 3209 patients (mean, 3.7 surveys/person; range, 1-22) after ACL reconstruction with a mean survey age of 35.2 ± 11.9 years (range, 13-72). A total of 4615 surveys were collected from 1813 patients (mean, 2.6 surveys/person; range, 1-17) after knee arthroscopy with a mean survey age of 47.4 ± 14.6 years (range, 11-88). For patients who underwent ACL reconstruction, the SANE rating had a moderate positive correlation of 0.66 to the total survey scores. For patients who underwent knee arthroscopies, the SANE rating had a strong positive correlation of 0.74 to total scores. There was minimal difference in correlations based on age group or sex. Bland-Altman analysis showed that the limits of agreement between the SANE score and the 2 surveys were met for at least 94% of patients in both patient groups. Conclusion: The SANE ratings exhibited moderate to strong positive correlations with the modified CKRS and IKDC subjective surveys after ACL reconstruction and knee arthroscopy for patients of all ages and both sexes.