If you are asking whether someone having a degenerative disc would make a difference I don't think it should if someone truly loves you, but it could if your potential partner, say, wants to share a very active lifestyle with you and now realises that won't be possible. In my view honesty is always the best policy so being up front is the best way to go.
Well, you will have to tell, better sooner than later. Either it will not matter for the other person, or it will. If it does, and you are rejected for being physically imperfect, the sooner you get rid of an incompatible partner, the better! If this goes on for months or years and *then* stands in the way of something - say, causes massive medical bills - the other person may feel cheated and will most probably resent it.