Mate don't stop doing SOHPs, just wear a belt and focus on using less weight to begin with as it really works your core muscles heaps. Once you build up your core, you'll be able to smash some bigger weight over your head no probs. Just start with a moderate weight and supplement with some seated dumbbell raises to begin with.
But wait until your healed up first, don't over stress your back. Hope that helps you mate, sux getting injuries.
EDIT: Also, make sure your really squeezing your abs/core when doing them so you take the stress off the back, you should have sore abs after a good session of SOHPs, as well as smashed shoulders too. It's to good an exercise to not do them.