First and foremost: You can't target parts of your body for fat reduction. You won't be able to target where you lose. So doing ab and arm exercises to reduce fat there won't work!
Additionally, "bulking up" on top won't happen... I assume you are female? You'll want to check out this article which debunks popular strength training myths: www.sparkpeople.com/resource/fitness_artic
Before you start any new exercise program, especially with an injury, you need to check with your doc. :) It's hard to work the body in isolation!