Hi Kim,
I think it's just your body getting used to a new architecture. For a long while, to avoid pain and to compensate for the loss of cartilage, your body twisted itself into the most pain free shape possible. It's not the best shape for someone with healthy hips, but it was the best possible.
I think this caused you to overuse some muscles and underuse (to the point of atrophy in some cases) others.
Now you are back to a normal hip, the rest of the body has to readjust. In some cases, some muscles are relieved because you're asking much less of them, but others that may be atrophied would suddenly be asked to bear the weight that they did before, maybe years before.
In my opinion it eventually works out, but that imbalance is not going away immediately.
So soreness, etc. was something I also experienced, but expected that the recovery would have a few extra twinges, especially with atrophied or underused muscles.