I would cut the damaged branch back pretty hard, either back to the main trunk or to a smaller diameter branch, if there is one. Don't leave a stub. It may slightly spoil the looks for this first year, but it should fill in over the summer.

If you still don't like the looks (and I have only seen 'Kaleidoscope' as a nursery pot, so I can't predict the eventual growth habit[s] - many abelias look better without pruning, as long as they have the room to grow), then you can take it to the ground in late winter/early spring - you can do that to most abelias and let them grow up again. I don't know if this one has the graceful, arching habit of other abelias or not, so can't say if it would look good after a while with pruning, or not.

Thanks, Dibbit. I'll take a close look as soon as I get home from work to see how far I need to take it back. Should I do this pruning now or at a later time? I'm not so much concerned about flowering as possibly stimulating new growth generally. Am I correct in assuming that pruning back will have that effect?

I'm a bit backward where pruning is concerned because in almost all cases I much prefer to let shrubbery assume its own shape. When an occasion arises that demands a cut here and there for the sake of the plant, I usually find myself at a loss.

I have no experience with the mature version of this variety but from what I've managed to research it should have a loosely mounded shape - perfect for the spot in my bed. It should grow to about 5-6 tall and wide. As beautiful as the foliage is already, that should be spectacular!

Thanks again for your advice!

Abelia is notorious to produce straight vertical stems if pruned into 2-3 years old wood, so if you still want to keep loose mounded arching shape of the plant you have to prune your broken branch all way down to the stab.
In a future just slightly prune tips of the branches when needed and it will keep its natural shape.

That's good to know, ego45. I'll take your advice and Dibbit's to cut all the way back. That's going to leave a bald spot but I hope that will fill in eventually.

It's not exactly in my budget, but I'm thinking about moving this "handicapped" abelia to a less prominent place and replacing it with a new one. There will be two in this foundation border and it might be best to get them started out "equal". Given the beauty of the foliage, I'm sure I can find another spot where a bit of irregularity in the shape of this one would not be a problem.