Hiya! Our kitty suffered a broken pelvis and damaged tail in a car accident on June 17, and is currently tearing around the house like there's nothing wrong.
Unfortunately I don't know the extent of her original injuries, as we took her in as a foster to look after her until she healed, then decided to adopt her...
I know for the first 2 weeks, she was kept in a cage at the shelter I volunteer at while she was healing, and also really didn't move much. We took her home after that, and she was really wobbly on her legs, and would walk a few steps and just flop over on her side purring looking for a pat
We kept her confined to a bedroom in our house for a good few days, and she started getting the strength back in her legs - I think she was quite stiff as much as anything.
Within a week of us having her (3 weeks after the accident), she had started jumping on things, and starting to run again - we tried to slow her down, but there was no chance. She's 8-10 months old and wants to play!
Now, she tears around the house, leaps on everything and has just healed so fast. When she's had a big play session, one of her legs splays out a bit, so we try to limit her play times, and she sits a little funny, but I think that cats have amazing heaing powers!
Just keep your boy rested, let him go at his own pace, and spoil him rotten