@lgreg This happens, and it could be a number of causes. Here are a few things to consider-
- As @steveinarizona said, the problem could be one or bot hips - make sure they are checked too.
- OLD SHOES Your walk changes after surgery, and if you are wearing shoes that have "worn in" to your old walk, this can stress your body. Get some good, supportive athletic shoes and see if this helps. Also, after hip surgery, I was told to wear supportive house shoes as well - not bare feet or slippers, and not crocs or slide on sandals.
- The height difference you mentioned. Sometimes a lift in the shoe on the shorter side can cause it, other times PT.
- Your gait has changed due to straightening your leg. PT can help you strengthen all the back, leg and hip muscles, and correct your walk if needed. This requires an individualized assessment by a rehabilitation therapist, not "cookie cutter" post-op exercises.

Have you tried any of these measures?