Shell retention with a cemented acetabular liner.

Abstract

The authors reviewed the indications, technique, and results of cementing an acetabular liner into a well-fixed cementless acetabular shell. Indications for this procedure include a worn acetabular liner in a well-fixed cementless acetabular shell as well as an unstable total hip construct where the shell is secured. To perform such a procedure, an adequate shell diameter is necessary to accept an acetabular liner that will enable 2 mm of cement mantle around it. If the shell has screw holes, there is no need to score the acetabular shell, but otherwise the acetabular shell must be scored to a 1-mm depth in a spiderweb configuration. As for the acetabular liner, it too must be scored to a 1-mm depth in a spiderweb configuration (which enhances torsional stability) as well as a circular configuration to provide optimal lever-out strength. We have evaluated 31 constrained liners and 30 nonconstrained liners with this preparation. The failure rate in the constrained liner series was 6%, and no failures occurred in the nonconstrained series. One dislocation occurred in the nonconstrained series where patients were typically placed in a brace or cast for 6 weeks. This option should be considered in cases with worn-through acetabular liners for unstable configurations when the acetabular shell is well fixed and is of adequate diameter to accept such a construct.