HI,
i had my 1 week post op with my nurse on Monday and she said I am ok to go to the gym now and do lower leg work but nothing high impact. IE running on the treadmill not allowed until 6 weeks but walking, cross trainer (but NOT using the arms), squats, leg raises etc all fine.
Basically you can do anything that doesn’t involve your chest muscles and arms and doesn’t involve high impact. When you get to 6 weeks you can go back to normal.