Should i do leg workouts with a torn acl?

Yes: The acl functions to stabilize the knee in rotation, shifting, and some translation. Associated problems are quadricep muscle weakness or inhibition. So workouts that improve quad function will improve associated symptoms. Quad exercises include exercise bike, squats, lunges, dips, and stair work.

Yes: Having a strong leg and thigh is helpful, in recovering from an acl injury and in getting ready for surgery to reconstruct. I suggest non impact, inline strengthening exercises. In addition, regaining range of motion and icing to get rid of any swelling is very important.