 Methods In a prospective, randomized, double-blinded, placebo-controlled trial with two parallel groups, 62 patients were treated. Bone tunnel width was measured by CT scans, while clinical efficacy was assessed by patient-administered outcome instruments WOMAC, IKDC 2000 up to one year following the ACL reconstruction in patients receiving either ACS Group A or placebo Group B. The investigators compared the levels and dynamics of IL-1b concentrations in the synovial liquid and examined the correlation between the levels of IL-1b at three different post-operative points. 