A banister is something to hold on the way up or down. It is read as support during change — a person, a routine or a belief that steadies you — and a broken one as support you can no longer count on.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.