don't know about 'putting the limb into the socket', but, if you watch "For Tomorrow We Die", Duncan cuts off Xavier's hand and when Xavier appears in season 2, he has a hook in place of his hand ---
so, we know limbs will not grow back on their own, but i haven't seen any references to limbs reattaching if they are held in place -- tho, that might be a possibility since that is even sort-of possible w/ mortals -- if you cut off a limb, the doc's can stitch it back, so i would assume if an immie held his arm against his shoulder, it would reattach ----
pure speculation -- but fun!!
good question!!