Ask your orthopod if he's ever done 30-rep squats himself, and how his knees felt afterward. If he hasn't, ask him why he feels so comfortable recommending them. The vast majority of 52-year-old human knees have a tear in some part of the meniscus, it causes no problems, and if you let this dumbass operate on your knee, you are crazy. Read the threads on this board about knees, and get back to your squats and deadlifts.