We had a papillon that had a similar issue. Collided with the big dog during some rough housing and came out with her back legs all wobbly. We had to keep her in a pen for a few weeks to prevent her from aggravating it but she eventually made a full recovery. Hoping your pup has a similar outcome.
Sorry dude, sending positive vibes your way!!! How old is Teddy?
We had a 2 yr old lab who ran upstairs in a house under construction and ended up falling out of the rough in for a slider door. He had a similar issue at first but ended up bouncing back really quickly after some initial swelling went down. Hoping for a similar outcome!