i was dropped from occ 181 due to a bad knee. turned out my acl and both menisci were completely torn, and i have since had surgery. i went in front of the board and was dropped, but i was told that i shouldn't have too much trouble getting back in, as long as i took care of my knee.
one of the guys that was dropped at the same time was there for his third and final time. i think that if you are dropped for medical reasons, it isn't too hard to get back in, as long as you get the proper waivers.