Arm Injuries From Too Much Applied Force

Situation:
Your friend is climbing somewhere high above you - they weigh about the same as you; let's say 80kg; mostly muscle on both of you.  In order to not lose track of them because it's dark, they have a rope around their waist which you have (incredibly foolishly) wound around one of your wrists. 

Inevitably, your friend falls.  Hurtles straight down to where you are (approximately 25 feet) and then keeps falling for another 30 or so until the rope goes taut and hauls you off the ledge.  You manage to catch a handhold with your free hand and hang on (barely) ...but that's still a lot of weight that just wrenched at your wrist.

So my question is: how much damage would your arm (and possibly attached body) sustain from an 80kg person falling about 55 feet and then snapping taut on the rope?  Especially when all your weight and their weight is now being held by your free arm?

Search terms:
I can look under dislocations or broken bones in google, but I'm more looking for an estimate of injury under a certain situation, and the uh ...situation is kinda hard to find on the world wide web.  So I'm hoping for estimates here, because I'm not sure this is easy to answer ^^;; 

Setting:
Not particularly relevant.  It's in an abandoned New York sewer system in the dark, for curiosity's sake...

Thanks for any help offered!