I do know that when her gait irregularities started showing up a few months ago and I Googled feline hip dysplasia, that was one of the first things that came up. I haven't brought it up with my vet as the chiro seems to be working, but I suspect it's not going to be such a good idea for an older cat, especially as it apparently relies on muscular support to fill in functionally for the bone which is removed, and she's now showing some age-related muscle-wasting in her hindquarters. I don't think she'd have enough strength to support herself after that kind of a procedure. (And I also have to wonder how cats who have it done when they're younger fare as they age, since a certain amount of muscle wasting is a normal part of the aging process).
She also has some minor curvature of the spine, and I'm sure that also affects things. But for now, the chiro seems to be helping, so we'll continue with that. So far, so good! (She was playing "fighting stallions" with Kira about half an hour ago. I love to see that!)