O3256 COMPARISON OF ACETABULAR SURFACE TREATMENTS IN ALUMINA ON ALUMINA CLINICAL TRIAL

Abstract

Aims: To compare acetabular surface treatments in alumina on alumina clinical trial. Methods: Utilizing new improved alumina ceramic materials and implant design, 514 hips were implanted in a US IDE prospective randomized study. All patients received the same press-þt hydroxylapatite-coated (HA) femoral stem. Two-thirds (349 hips) received an alumina ceramic bearing surface, while one-third (165 hips) received a cobalt chrome on polyethylene bearing. The alumina group was further divided with approximately one-half receiving a porous-coated titanium shell and alumina insert (172 hips Ð System I), and one-half receiving an arc deposited titanium shell with HA coating and alumina insert (177 hips Ð System II). System III, the control group, had a porous-coated titanium shell and polyethylene insert. All acetabular shells were of identical external geometry. Results: At latest follow-up, minimum 2 years (2–4 year range), differences were noted in the pattern of development of radiolucent lines around the acetabular components. Radiolucent lines were noted most commonly in De Lee Charnley Zone 3 in porous-coated shells (25/164 hips Ð System I, 33/151 hips Ð System III respectively). Radiolucent lines in Zone 3 were absent in the arc deposited with HA shells (System II) (p=0.001). Conclusions: These results appear to demonstrate that PSL style cups with arc dep and HA coating may improve levels of primary þxation versus that of porous-coated acetabular components.