Does an enhanced surface finish improve acetabular fixation in revision total hip arthroplasty?

High-porosity "cancellous metal" coatings have been introduced to increase the fixation and biologic incorporation of acetabular cups. The strength of initial fixation provided by a cancellous metal cups vs conventional alternatives in the deficient revision acetabulum was investigated. Cancellous, plasma-sprayed, and beaded cups (n = 9) were implanted under controlled conditions into a validated model of the revision acetabulum. The greatest differences were seen in resistance to catastrophic (spin-out) failure that, for the cancellous shell, averaged 1076 ± 265 N, which was 25% greater than the plasma-sprayed implant (859 ± 214 N, P = .04) and 218% greater than the beaded implant (338 ± 123 N, P < .01). The cancellous coating also provided greater resistance to ultimate failure. These results suggest that these new cancellous metal coatings may represent a promising alternative for fixation in revision total hip arthroplasty.