The research procedures will be conducted at the University of Kentucky (UK) Medical Center. Participants will need to come to the UK Healthcare at Turfland located at 2195 Harrodsburg Road in Lexington, KY. Participants will be asked to come to this location seven times during the study. Each of those visits will take about 30 minutes. All exams and questionnaires will be administered during the otherwise necessary routine visits for any participant who has suffered an ACL tear. No additional visit is necessary. The total amount of time commitment for participation in this study is about 6 1/2 hours, over the next 2 years.