In patients with persistent pain after total replacement of the hip, arthrography during aspiration has been found to be useful for verification of the proper intracapsular placement of the needle and for the diagnosis of loosening of the prosthesis. The presence of soft-tissue abscesses or sinuses can also be demonstrated on occasion before the clinical picture of infection is definitely established, as well as other rarer pathological entities. The technique is most useful when radiolucent acrylic cement has been used, but it is also helpful for the diagnosis of complications when radiopaque acrylic cement has been used.