Prevalence of Early Knee Osteoarthritis Illness Among Various Patient‐Reported Classification Criteria After Anterior Cruciate Ligament Reconstruction

OBJECTIVE To compare the prevalence of participants meeting different patient-reported criteria for early osteoarthritis (OA) illness after anterior cruciate ligament reconstruction (ACLR). METHODS Participants completed the Knee Injury and Osteoarthritis Outcomes Score (KOOS) at a single time-point at 5.0-7.9 months post-ACLR. We used established KOOS subscale criteria (i.e., Luyten_Original and Englund_Original) to define patient-reported early OA illness. A two-by-two contingency table and McNemar's test were used to compare the prevalence of participants that met the Luyten_Original versus Englund_Original KOOS criteria for early OA illness. These analyses were repeated using KOOS subscale thresholds based on established population-specific patient acceptable symptom state (PASS) within the Luyten and Englund KOOS criteria (i.e., Luyten_PASS and Englund_PASS). RESULTS A greater prevalence of participants with ACLR met the Luyten_Original criteria (n=165, 54%) compared to those who met the Englund_Original criteria (n=128, 42%; χ2 =19.3, p