Cementless acetabular replacement in patients with rheumatoid arthritis: a 6- to 14-year prospective study

Sixty-three consecutive patients who had 82 Harris-Galante porous acetabular cups (HGP1) (Zimmer Inc, Warsaw, IN) implanted for the treatment of rheumatoid arthritis were prospectively assessed since 1986. At last examination, 12 patients (16 hips) had died, and 1 patient (1 hip) was lost to follow-up. A total of 65 hips in 50 patients were available for the latest review. The follow-up period was 6.8 years to 14 years (mean, 9.1 years). There had been 6 revisions: 1 for deep infection and 5 for polyethylene cup wear. Survivorship analysis for all failures estimated that 75% of hips would still be revision-free after 4558 days (12.5 years). Polyethylene wear has been identified in a further 7 cases at last examination. The average linear cup wear per year was 0.05 mm(range, 0.00-0.66 mm). There were no cases of acetabular loosening or acetabular migration. These results demonstrate the excellent durability of fixation of the HGP1 cups in patients with rheumatoid arthritis. However, a 32-mm head should probably not be used with this cup given the high associated incidence of polyethylene wear.