Leafless keikis on a den phal cane
 

I now have two keikis on a damaged cane, lots of roots, but leaves dry up before opening. The cane is now getting pretty shriveled. Should I cut the keikis off and pot them? Don't leaves need to be present for it to grow? How much of the cane should I leave attached? I've successfully potted keikis before, but only phals with leaves.

If the underlying stem is dying, your hand is forced. The keiki leaves are dying because the stem can't provide them enough water.

Some people cut up the old stem and leave a small piece attached to the keiki. Others carefully cut keikiis off the stem. Still others cut the whole old stem at the base, and lay it sideways on top of a tray of sphagnum moss. Whichever method you choose, high humidity around the keikiis is important.

If the keikiis are large enough and you can water them enough, they will push new growths from their bases, and the new growths should have healthy leaves. If they aren't large enough yet, they will probably die. There's no way of knowing what will happen without trying.

Nothing to lose then I guess. The cane was broken, but still attached after I fell while carrying it last April. I attempted to salvage it by splinting it, but I guess that didn't work. The parent plant is about 4 feet across when in bloom. Last November, there were 15 new canes in bloom for 25 total blooming canes and about 35 flower sprays. I should have taken pictures of it.

That must be something to see.

Sounds like you're not going to lose the whole plant, so it's less of a worry.