Hello Sara. Since I am only one week post op, I haven't discussed with my doctor when I can resume horsie activities. I would say that you would need to explain to your doctor that you aren't just getting in a saddle and running around. You are using your legs a lot and they will have to be strong and able to bear weight.
I have a 15 year old quater horse whom I just use now for pleasure riding. He is my dead broke horse that I will probably get on first. The other is my 5 year old paint mare that I rescued from an abusive situation last year. I will make sure that I at 100% before getting on her again since I need to be slow and steady with her.
Good luck with your leg and I hope that you are back in the saddle again soon.