Welcome to BoneSmart!
Yes, it's not at all uncommon for our members to report either an improvement in another area (yay!) or a new pain (not a yay...). Here's why...
(I am hoping your post didn't autocorrect from "impingement" to "improvement" but the basic answer is the same)
Our arthritis-affected joint, over time, creates a lot of structural changes as the body tries to adapt to compensate. Some muscles and tendons lengthen and stretch while their counterparts contract and tighten. This can happen below our level of consciousness even as these forces start skewing our pelvis, our posture, our gait.
All at once in surgery everything is essentially reset by the surgeon. Part of recovering from a hip or knee replacement, besides the actual healing, is a re-making of our structure to again adapt.
We'd love to hear more about your own experience with your hip and sacro-iliac!!
Which hip was replaced, on what date? How has your overall recovery been going?