I know exactly what you are going through. Sasha ad an FHO because of Leggs-Calves-Perthes. I started a thread in March of 2015. Here is the link.
http://www.yorkietalk.com/forums/sic...s-disease.html
Sasha never cried either. She is one tough cookie. But the doc said she must have been in pain with every step. She was about 13 months and just under 4 pounds when she had the surgery. The good news is she came through like a champ. I remember sitting in the chair and holding her for 2 hours after the surgery. If you go to my profile and look in my album there is a pic of her hip after the surgery. It is not pretty. How well she does after the surgery will 100% depend on you. Keep her calm (which means keeping her in a cage most of the time). Follow all of the doc's orders. Keep the cone on him even though he won't like it. Water therapy is great either at home or with a professional. The outcome of these surgeries is very good. Sasha loves to go outside and run. I call her my little wind chaser.
It will be tough but many dogs have had this procedure with wonderful results. We will keep you in our prayers.