While surgical options are successful at restoring the stability of the knee joint, the damage suffered during the injury extends beyond the ligament and predisposes the majority of patients with an ACL tear to early wear of the articular cartilage. We hypothesized that early antiinflammtory intervention post-ACL reconstruction reduces inflammatory and chondrodegradatory biomarkers, and improves patient reported outcomes. We will enroll patients with acute ACL tears and follow these patients for one year after surgery using biomarkers of cartilage breakdown, MRI, functional testing protocols, and patient reported outcomes to assess if the early use of HA after surgery can potentially reduce or eliminate the progressive cartilage breakdown seen in young patients with ACL injuries. The potential benefit of such a treatment strategy is very high, as it might be able to delay or eliminate stifling knee pain and stiffness in young athletes when they reach the most productive years of their lives.