Bony ingrowth fixation of newly designed acetabular components in a canine model.

Implantation of a newly designed acetabular component with a porous coating has resulted in superior fixation when compared with acrylic cementation in the short term. Experiments in dogs demonstrate rapid ingrowth within the porous layers, resulting in rigid fixation of the acetabular components despite defects in the prepared bony bed. Acute infection prevents bony ingrowth and causes loosening. The absence of any foreign-body response to the titanium fiber mesh components suggests that this is a biocompatible metal. The fixation has been excellent; progressive or delayed loosening is not encountered once successful ingrowth is achieved. Progressive radiolucent zones generally do not appear in the short term but when visible soon after surgery, may consolidate and disappear. Ingrowth fixation of acetabular components appears to offer an attractive alternative to the use of acrylic cement and may even be feasible in patients with periarticular bony abnormalities.