Fig. 9

A A 54-year-old male was diagnosed with right hip prosthesis loosening 24 years after THA [20]. B AM model showed severe osteolysis around the acetabulum in the superior and inferior acetabulum, ischial ramus and pubic ramus. Some cortical bone remained in the ischial ramus on AM model, but it was proved to be radiopaque bone cement in operation and the ischial ramus was completely destroyed (We had reported this specific intraoperative finding and other misleading cases under AM models in another study in detail [20]. The vertical and rotational stability could not be obtained. C Although the operation was managed with a customized cage, we believed that the initial stability was insufficient because the cage was fixed to the ala of ilium only by a screw in the superior. Such patients might benefit more from customized hemipelvic prosthesis [20]