My dogs back legs gave out, is it okay for him to sleep with his legs stretched under his body?

I have taken him to the vet and they said he had hip dysplasia, but now that he can’t adjust himself I need to move him around, and I’m wondering how I should put him to sleep. Before, he would cuddle the back of my knee and put his back legs on top of my knee and his head on tops of his own paws (if that makes any sense hahahaha) if anyone has gone through this and knows of a better way, please let me know, I’m still going to ask my vet but she’s closed until Monday.