MRI Evaluation of Graft Maturation Following ACL Reconstruction

Inclusion Criteria: * ACL tear and reconstruction; no other knee ligaments needing reconstruction * Primary (first-time) ACL tear in the affected knee * ACL injury occurred less than 12 months before ACL reconstruction * Have no contraindications or allergies to the treatment administered * Have current imaging studies (plain radiographs and MRI exams within the past 12 months) of the knee to rule out other etiologic diagnoses * Patient underwent ACL reconstruction with a Bone-Patellar Tendon-Bone (BTB) graft harvested from the same knee (ipsilateral autograft) with the Active Matrix tissue * Able and willing to comply with the post-operative study follow-up schedule Exclusion Criteria: * Prior surgery on the index knee within 12 months of enrollment * Steroid injection into the index knee within 6 weeks of enrollment * Chronic ACL tear whereas the injury occurred more than 12 months ago * Multiligamentous injuries whereas any ligament (MCL, PCL, or PLC) in addition to the ACL needs to be reconstructed * Patient underwent ACL reconstruction with a hamstring tendon, Achilles tendon or quadriceps tendon graft (any graft other than a patellar tendon BTB) * Contraindication to MRI (eg, implanted devices incompatible with MRI). * Chrondral lesion of the knee that requires treatment during ACL reconstruction surgery * History of advanced osteoarthritis of the knee or patella-femoral joint; KL grade III or higher * History of malignant tumor and osseous metastatic disease, * History of chronic pain disorders (i.e., fibromyalgia), * Current substance abuse (drug or alcohol), by the investigator's judgment, * Females who are pregnant, nursing or breastfeeding, or who intend to become pregnant during participation in the study. * Currently participating in, or have been recently exited from (within 30 days from enrollment in this study), or plan to enroll in another clinical study for a bone allograft or drug that may impact participation or outcomes of this study, * Currently involved in any injury litigation or workers compensation claims, * Has a condition, disorder or other factor that, in the investigator's opinion, would interfere with study participation.