18 Months Post Op THR Have Chronic Hip Subluxations With

18 months post op THR have chronic hip subluxations with severe pain. Scan showed no loosening or infection. Have psoriatic arthritis and severe over pronation and foot arthritis. Stairs and certain movements cause hips to subluxate. When I hold the ball area and move hips, I feel popping and grinding. I am 51 and about 10 pounds overweight. Use to be extremely active. Thanks for your help.