In a prospective study, thirty patients in whom a Charnley hip
prosthesis was implanted with cement (methylmethacrylate) and fifteen who
received a prosthesis without cement were studied. The activation of
complement, as indicated by the release of anaphylatoxins (C3a and C5a),
reduced activity of whole complement, and decreased levels of C3, C4, and
C5 in plasma, was evaluated. Activation of complement was found when
methylmethacrylate was used. In patients in whom components were fixed
without cement, no formation of anaphylatoxins occurred, and only slightly
reduced whole-complement activity and concentrations of C3, C4, and C5 in
plasma were found. A dose-correlated release of the anaphylatoxins was
found when monomethylmethacrylate was incubated in fresh serum. One
explanation for the hemodynamic instability in these patients might be the
biological effects of anaphylatoxins that are released in association with
fixation by cement.