[Additional information regarding periarticular ossifications after total hip replacement (author's transl)]. / Beitrag zur Frage periartikulärer Verkalkungen nach totalendoprothetischem Hüftgelenksersatz

Residual monomer originating from acrylic bone cement is not the origin of periarticular calcifications after hip joint replacement. This has been demonstrated by gaschromatografic detection of monomeric methylmethacrylate in the liquid of the joint space. Up to 200 microng/ml monomeric MMA could be demonstrated in the first days after the operation only. The concentration of residual monomeric MMA in the bone cement is 1% to 4%. It is deminished time dependently by diffusion of the molecule in the surrounding tissue. All determined concentrations of monomeric MMA in the joint liquid are below the toxic range for tissue demage.

[Influence of the bone-cement mixing time on hypotonic blood circulation reactions in hip-joint replacement surgery]. / Der Einflubeta der Anrührzeit des Knochenzements auf hypotone Kreislaufreaktionen bei Hüftgelenksersatzoperationen

The amount of methylmethacrylatemonomer that is released into the blood-stream, during the alloplastic replacement of the hip-joint, depends on the time taken to prepare the bone cement(so-called extracorporeal polymerization-time). In vitro experiments reveal that the release of monomers depends on the preparation time. Gas-chromatographic monomer determinations show, that by prolongation of the preparation time from 2 to 5 minutes, the amount of monomer released into the blood-stream is decreased by a factor of 7. With the increase in preparation time the number of hypotonic circulatory reactions caused by the monomers will decrease. Extension of the extracorporeal polymerization-time from 2 to 5 minutes decreases the incidence of intra-operative circulatory depressions from 95% to 26%. These results were obtained by intra-arterial measurements of the blood pressure in the radial artery.