Sorry, things have been hectic here so I've been AWOL...
Is there any way you can hold him back to sleep in his room when he wakes early? Like sit on a chair in the dark and just...sing a lullaby? Play soft music?
Have you tried pain meds? If so, any difference?
On the other hand, if he's waking that early anyway, maybe just let him sleep with you after hubby gets up for work? I'd try giving some pain meds when he wakes and snuggling, see what happens.