Cement Anchors With Screw Holes For Liner Cementation Into Cementless Acetabular Metal Shells.

: This mechanical study was conducted with the shellcement interface in order to construct an acetabular metal shell, and to fix a polyethylene liner with bone cement. Six types of models were tested, with all cementations performed under 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 2 different configurations with 3 holes at 3 mm depth. The strength of adhesion increased with the use of a cement anchor, and with an increasing length and number of anchors. The application of a cement anchor with a screw hole is clinically useful for increasing the mechanical strength of the shellcement interface.