This happens a lot to African Violets. Normally the stem grows along the ground and roots in along the exposed trunk. After a few years the original roots die and the new ones take over.
Remove all of the leaves except the newest 10 or so, including the tiny ones in the middle. Then remove all but 1" of the stem. Stick it in a 4" or smaller pot with African Violet soil and water well. When it stops dripping put the whole thing, pot and all into a large plastic ziplock bag and put it in an East or North-facing window with no blinds or curtains. It should root and start to show signs of recovery in about a month.
Repot it every other year or when you start to have a noticeable trunk. When you do, remove an inch or so from the bottom of the rootball and bury it deeper to cover the trunk.