Stv,
Most of your report was over my head, but the great news to me was "slight to modererate OA of the right hip and very slight narrowing of the left". If I understand the situation correctly, you have a long way to go before total replacement is needed. As I said, I had what looked like severe OA on the X-Ray plus the physical examination of the removed hip confirmed that.
Having no medical training, I suspect that the old injuries present you with more problems than the hip by itself. I have found that old injuries cause new ones as our bodies and our behaviors are altered to compensate for them. This causes imbalances and stress in other places and they ultimately fail.
I remain a proponent of the "use it or lose it" philosophy for those of us over 50. Do what you can, have fun and make the best of what God gave you. I think that is all we can do!