Porosity reduction in acrylic cement is clinically irrelevant.

Evidence from studies on migration raises serious doubts regarding the part played by fatigue failure of acrylic bone cement in the genesis of aseptic loosening of the components of total hip arthroplasties. Moreover, the viscoelastic properties of cement raise serious doubts concerning the relevance of conventional laboratory fatigue studies to the in vivo behavior of acrylic cement. It is not surprising that there is considerable clinical evidence that reduction of porosity in acrylic cement is of no relevance to the long term outcomes of total hip arthroplasty. These matters remain controversial, and randomized prospective trials would be necessary to settle the issues. For various reasons, such trials are unlikely to be performed.