I had a similar accident as you. A 70 lb black lab ran head first into the side of my right knee. When I went to the ER they said it was just a sprained knee. A day later, they called to say I have TPF. I then went to a specialist who saw something on the xray and requested an catscan. It was determined that the top of tibia was shattered. I had surgery on 7/8/14, they put a plate and 8 screws along with bone graft to repair the damage. I was NWB for 7 weeks then started with a walker. I have now graduated to a cane.
While I was lying around I would do ankle stretches and bending my knee. I wish I had know to squeeze my quad because that seems to be where I am having issues during my recovery. I also feel that I should have went to a physical therapist during my 7 weeks NWB. I think they would have giving me different exercise to my recovery go better.
Good luck with you recovery,