Eighty-three patients with Rheumatoid Arthritis who had 96 uncemented acetabular components were followed postoperatively for 4 months to 5 years and 2 months. Thirty-eight of these hips had protrusio acetabuli and needed bone grafting to the medial acetabular wall. Hydroxyapatite ceramics were used in 7 of 38 hips. Clinical results and roentgenographical analysis were evaluated. All grafts appeared to have united roentgenographically and protrusion did not progress. Radiolucent line around acetabular cup was seen in some cases, but loosening of acetabular cop was not seen. The results of this study suggest that the acetabular cup fixed onto the grafted bone for a press-fit.
