The causes of hip lock and popping could be many including subluxation of hip due to shallow hip socket, acetabular labrum tear, systemic arthritis like psoriasis, other arthritis or bony spurs, or structural abnormality in the
joint. You need to consult an orthopaedician surgeon to investigate in detail and an Xray of the affected hip joint. Certain conditions could be managed with injections, arthroscopic repair and reconstruction. Hope this helps. Take care.