Sure, you can still play baseball or basketball. You can even play with your childhood heroes, provided you can foot the bill for fantasy camp (and you can miss six weeks of work - one for the camp, and five recovering from a torn achilles or a blown ACL). But there's a far easier (and less expensive) way to relive your youth. Cop another pair of those sneakers you had in sixth grade, and let all those feelings rush back. No surgery required.