Chinese Ethnicity Is Associated With Concomitant Cartilage Injuries in Anterior Cruciate Ligament Tears

BACKGROUND: Chinese ethnicity is associated with the presence of knee osteoarthritis. This raises the possibility that it may similarly be associated with concomitant meniscus and cartilage injuries in patients with anterior cruciate ligament (ACL) tears. There are currently no published data on the effect of Chinese ethnicity in this regard. PURPOSE: The primary aim was to determine whether Chinese ethnicity is associated with concomitant intra-articular injuries in patients with ACL tears and to verify the correlation of age, sex, body mass index, mechanism of injury, cause of injury, and presence of bone contusions on magnetic resonance imaging with such injuries. A secondary purpose was to determine the optimal time frame for surgical reconstruction in patients with identified risk factors for concomitant injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The medical records of 696 patients from a multiethnic population who underwent ACL reconstruction from January 2013 to August 2016 were retrospectively analyzed. Univariate and multivariate logistic regression analyses were performed to identify patient factors that were associated with medial meniscus tears, lateral meniscus tears, and cartilage injuries. Further univariate analysis was conducted to determine the earliest time point for surgery, after which the rate of concomitant injuries was significantly higher. RESULTS: Over half (69.1%, n = 481) of our study population sustained at least 1 other concomitant knee injury. Meniscus tears were most frequently associated with ACL tears (24.1% medial, 25.6% lateral, and 15.5% medial and lateral meniscus tears). Cartilage injuries were present in 18.4% of our cohort. Chinese ethnicity was associated with concomitant cartilage injuries. Increased age (≥30 years) was significantly associated with cartilage injuries and male sex with medial and lateral meniscus tears. Among patients with these factors, significantly fewer medial meniscus tears and cartilage injuries were noted when surgery was carried out within 12 months of the index trauma. CONCLUSION: This is one of the first studies to have identified an association between Chinese ethnicity and concomitant cartilage injuries in ACL tears. This study also found an association between increased age and an increased prevalence of cartilage injuries. Male sex was associated with both medial and lateral meniscus tears. Definitive surgery should be performed within 12 months of the index injury to minimize further intra-articular injuries.