Highly porous metal acetabular components have emerged for revision hip arthroplasty. However, superior mechanical stability over traditional cementless components has not been demonstrated. Three different cementless acetabular components, including 2 highly porous tantalum designs, were inserted into hemipelvis specimens with a superolateral defect. Mechanical testing was performed to failure using a servohydraulic testing machine. The porous tantalum designs exhibited superior stability over the traditional cementless implant (P < .05). There was no difference in mechanical stability between the rigid modular tantalum shell and the more flexible revision tantalum shell (P > .46). In acetabular revision, highly porous tantalum acetabular components provide superior mechanical stability. However, these results suggest that improved frictional resistance is a more important design feature over implant flexibility with this particular implant.
(c) 2010 Elsevier Inc. All rights reserved.