Effects of hydroxyapatite on titanium foam as a bone ingrowth surface in acetabular shells: a canine study.

This study investigated a highly porous titanium foam with and without a PeriApetite coating as an alternative surface for implant fixation. Twelve mongrel canines received staged total hip replacements under International Animal Care and Use Committee (IACUC) approval from our institution. Animals were randomly placed in three- or six-month groups for sacrifice. Seventeen total hips were available for evaluation. The area and depth of ingrowth was measured by SEM. At three months, PeriApetite Ti foam had 37% more depth and almost 10% more bone ingrowth. Both groups were found not to be different at the six-month mark with over 36% of ingrowth calculated on SEM. The results prove not only that titanium foam is a viable ingrowth surface but also that PA coating can enhance the time to bony incorporation.