Larry,
Unfortunately, our joints do not work in isolation. The body is very integrated, and every joint works in coordinations with the others around it.
In the lower extremities, if the opposite limb has difficulties, it can affect the gait cycle. So, if you are having difficulties in the right knee, it could "throw off" the way your left hip works.
If you are having quite a bit of difficulty, you need to speak with your surgeon as soon as possible. You do not want to develop poor gait biomechanics, that can not only alter your gait, but put abnormal stresses across the artificial joint, which could lead to the joint wearing out early.
The surgeon can evaluate your gait and determine if something needs to be done, and when.
Good luck.