Danny
How awful for you all - poor Charlie.
Unfortunately, we went through exactly the same thing with Scooby when he was 6 months old. He was attacked by two dogs, was chased across a road and hit by a taxi. He fractured his back right leg and had to have it plated and pinned. He nearly died from shock and they couldn't operate for two days but luckily he came through and they were able to operate and he has made a full recovery.
Like you, we were worried he would lose a leg but the vet assured us that because he was so young he would probably recover without so much of a limp but had he been older it may have been different.
How old is Charlie?
Modified to say: Don't worry about the length of time in theatre, Scooby was down for a good 4 hours and they said it had been a tricky operation. If they had amputated it would have been quicker I'm sure. They may be just trying different methods of pinning etc., they did with Scooby, that's why it can take a while.
Crossing everything for you all x