Fixation Using Acrylic Cement

Abstract

Acrylic cement was successfully used for rigidly fixing artificial hip components to the bones. This fixation method was therefore used in the first artificial knees that were invented, starting in the late 1960s. However it was soon found that loosening at the bone-cement interfaces frequently occurred with most designs. This was attributed to the combinations of compressive and shear forces acting across the knee, to inadequate surface area of certain components, and to ineffective fixation posts. Later, experiments showed that in order to improve the bonding over the entire interface, the cement needed to penetrate the trabecular bone surfaces by at least 2–3 mm. Subsequently cement fixation became much more reliable, but loosening can still occur due to extreme situations. Whether a cemented interface would be durable indefinitely was investigated by Kenneth Mann at Syracuse University. It was shown that over time, the interface weakens due to bone resorption, but whether this will eventually result in symptomatic failure remains to be determined.