That is what I suspected, however, how many days post surgery are you know?

What I meant about atrophy is the time post-surgery, although how and what you ate before surgery would no doubt be helpful, it is just a few days of immobility, limited movement due to surgery and resultant atrophy that can be significant.

If you previously trained, the it is likely that you will regain to prior level of activity more quickly. The key is really get going asap.

I don't doubt that you can get back to 100%, but I think it is everything you do - including diet (high in protein to alleviate muscle loss), physiotherapy, relaxation and rest to optimize all aspects of your recovery.

Regards