In reply to Yorkshiregirl:
Youch!! Painful.
I dislocated my left elbow though it wasn't fractured. I did that in Germany and it was put in a cast. When I came back to the UK they said it better off without the cast and removed it straightaway. I still lost some mobility in my elbow. I can't bend it as far as my other arm and it's subsequently less good at locking off now. It's not a huge difference but noticeable to me and as I climber I'd have preferred to have the same range of movement as the other arm.
So the first thing I would say is try to get your arm moving as soon as possible after the cast is removed. Maybe see if you can get the cast removed early if possible - though I guess that depends on the fracture. For the dislocation part I was told there was no need for a cast at all. My arm could have just been put in a sling the whole time and I probably wouldn't have lost that mobility.
In terms of staying strong there is a theory that the body tries to keep some balance so that by training one side you'll also be helping the other side too.
For exercise anything that is done with a dumbell can be done on one side only: curls, rows, tricep extensions, overhead press and much much more. Also most training with a cable machine (or pulley) can be done one handed. And some exercises with rings (or rather ring) or fixed TRX.
If you're using a bar even though you can't do pull ups there might still be some stuff you can do. You could do one arm lock offs - and if not strong enough then with some assistance like a pulley and weight or theraband attached to a harness to remove some weight. You could also do the negative part of a one arm pull up with assistance too - or even just part of the movement at first.
Same thing with a fingerboard: pulleys or theraband to reduce the resistance to a manageable amount.
There should also be a fair amount of core exercises you can still do, particularly floor based stuff: leg raises, hollow body, windshield wipers, v - ups etc.
Try to maintain your body weight while your waiting for your arm to heal. If you lose weight it will be the muscle that's not getting used that goes first. But ultimately you will lose some strength of course and there's no way round it. Start climbing again as soon as you can but go really gently at first - almost any exercise will make your arm stronger. Build up slowly and enjoy the process.
Post edited at 19:01