i have the exact same thing.. except in my right arm. i've slammed numerous times on it, but just recently i was trying to ollie a double set, kept sticking on the landing and the weight of my body went right onto my elbow like three times in a row. i'd obviously had swellbows before that, but not that big. my arm was fucked and now i can feel shit moving around in it too. i'm not sure if its bone, but it has a sort of cartilage-y feel to it. and where mine is isn't on the point.. its up like an inch or so.