I'm another one with a comorbid autoimmune inflammatory arthritis, related to ankylosing spondylitis. Like AS, my psoriatic arthritis/undifferentiated spondyloarthropothy affects my hips, sacroiliac joints, spine, and most every other joint (in my case, and in many). If your pain is chronic, ask to be referred to a rheumatologist to get checked out for the spondyloarthropothies.