Injury pathology at the time of anterior cruciate ligament reconstruction associations with self-assessment of knee function

Objective: To evaluate the association of preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) and structural injuries reported at the time of anterior cruciate ligament reconstruction (ACLR). Design: Cross-sectional study. Setting: Three medical centers in California. Participants: Primary ACLRs (N = 636) performed between January 2009 and June 2010. Independent Variables: The 5 KOOS subscales: pain, other symptoms, activities of daily living (ADL), function in sport and recreation (Sport/Rec), and quality of life (QoL). Main Outcome Measures: Associated injuries (cartilage, medial meniscus, lateral meniscus, other ligaments), identified at the time of ACLR. Results: Sixty-eight percent of the cohort was male and the median age was 26 years. No gender differences in KOOS were observed. No KOOS differences were observed by race, except in Sport/Rec. Younger patients reported higher KOOS. Pain and ADL scores were not associated with any concurrent injury. A 10-point increase in KOOS symptoms subscale was associated with 22% higher likelihood of isolated ACL, 13% lower likelihood of medial meniscus injury, and 10% lower likelihood of lateral meniscus. A 10-point increase in the KOOS Sport/Rec subscale score was associated with 8% higher likelihood of isolated ACL and 9% lower likelihood of medial meniscus injury. A 10-point increase in the KOOS QoL subscale was associated with 15% lower likelihood of medial meniscus injury. Conclusions: Weak associations between the symptoms, Sports/Rec, and QoL subscales and structural injuries at ACLR were observed. The KOOS and its subscales are not useful as indicators of the pattern or severity of preoperative injury of patients presenting for ACLR.