I'm not sure how feasible it is, but perhaps after Luke escapes the wampa and passes out in the snow, the wampa could once again drag him to his lair.
Even less feasible idea: the first time, it's roughly the OOT version (plus whatever weirdness you want to add to it). I.e., we see an arm fall off but no reaction shot. The second time around, we see the reaction shot, which will have been altered to appear as though both arms are now missing.