COMPARISON OF DIAMETRAL SHRINKAGE OF CENTRIFUGED AND UNCENTRIFUGED SIMPLEX P(R) BONE-CEMENT

Reducing the porosity of bone cement substantially strengthens the cem ent in fatigue, However, concern has been raised that reducing the por osity of the cement would increase the shrinkage of the cement and thu s compromise the cement-bone interface. We measured diametral shrinkag e of cement mantles prepared with and without centrifugation of the ce ment, Four cement preparations (centrifuged and uncentrifuged mixed wi th monomer at either room temperature or O degrees C) were used to for m cement mantles of four different thicknesses (2, 4, 6, and 8 mm) aro und a stainless steel rod, We conclude that porosity reduction dramati cally increases the fatigue strength of bone cement without substantia lly changing the diametral dimensions of the polymerized cement when s tudied in the shape and volume of a cement mantle that would be used f or total hip replacement. (C) 1995 John Wiley and Sons, Inc.