In this study, centrifugation did not alter the static or cyclic
fracture properties of bone cement. Tests of fracture toughness and
fatigue-crack propagation of centrifuged specimens of commercial cements
(with and without antibiotic additions) demonstrated no significant
difference from control values. Among the cements tested, Palacos (with and
without antibiotic) was found to have a significantly higher fracture
toughness than either Simplex or Zimmer. We attributed this difference in
fracture toughness to the higher molecular weight measured for the Palacos
cements. For the tested cements, only Simplex had a significantly greater
volume contraction on setting due to centrifugation. The results of our
study demonstrate that centrifugation of bone cement does not improve the
cement's resistance to fracture in the presence of surface imperfections,
such as those found at the bone-cement interface.