Isolated ACL versus multiple knee ligament injury: associations with patient characteristics, cartilage status, and meniscal tears identified during ACL reconstruction.

Objectives: The objectives of this study were to determine (1) if patients undergoing reconstruction of an isolated anterior cruciate ligament (ACL) tear had different characteristics (age, gender, body mass index [BMI]) than patients undergoing ACL reconstruction (ACLR) with multiple knee ligament (MKL) tears and (2) whether there was a difference in prevalence of articular cartilage injury and meniscus tears between these two groups.

Methods: Patients undergoing primary ACLR between February 2005 and June 2013 were identified through an ACLR registry. Patients were grouped by whether they had an isolated ACL tear or an ACL tear associated with another knee ligament tear. The study cohort was analyzed to identify differences in patient characteristics and cartilage/meniscus injury patterns between the groups.

Results: Of the 21,377 ACLR cases enrolled in the registry during the study period, 2.5% (n = 549) had MKL tears. The MKL group had more males (73.2% vs. 62.8%, p < 0.001) than the isolated ACL group. The MKL group also had a higher percentage of patients with a BMI greater than 30 (31.1% vs. 22.7%, p = 0.0002). When adjusting for these variables, any articular cartilage injury was equal in the two groups (OR = 1.01, CI 0.82-1.25, p = 0.922), while medial femoral condyle injury was less common in the MKL group (OR = 0.73, CI = 0.56-0.07, p = 0.28). The likelihood of any meniscus tear was lower in the MKL group (OR = 0.56, CI = 0.47-0.67, p < 0.001) as was the likelihood of medial meniscus tears (OR = 0.53, CI = 0.44-0.65, p < 0.001).

Conclusions: When comparing patients with MKL tears versus isolated ACL tears at ACLR, there was a higher percentage of males and patients with BMI over 30 in the MKL group. Medial femoral condyle articular cartilage injury, any meniscus tear, and medial meniscus tears were less common in patients with MKL injury compared to patients with isolated ACL tears.