High risk of osteoarthritis in an obese patient. As far as OA & surgery is concerned, most young patients donot face this issue unless they have a concomitant chondral injury. Cartilage cant be regrown by its own after maturity. Once damaged, theres nothing much that can be done for it. Seperate set of surgeries are there to deal with chondral defects. The time lag between acl tear and surgery determines most of it.