Effects of cement anchors with screw holes for cementing a liner into a stable, cementless acetabular metal shell: A laboratory study

Abstract

A mechanical study was conducted on the shell-cement interface in order to construct an acetabular metal shell, and to fix a polyethylene liner with the bone cement. Six types of models were tested. All cementations were performed under the similar conditions. The “lever out” test was conducted 3 times for each group in order to measure the dissociation strength. The average dissociation strength values were 11.5 N·m for those without screw holes; 33.6, 34.7, and 78.7 N·m for those with single holes at 1-, 3-, and 6-mm depth, respectively; and 41.3 and 101.1 N·m for the different configurations with three holes at 3-mm depth. The strength of adhesion increased with the use of a cement anchor and with increased lengths and numbers of anchors. The application of a cement anchor with a screw hole is clinically useful for increasing the mechanical strength of the shell-cement interface