The strength of a cement acetabular locking mechanism

To minimize the morbidity associated with revision of a well-fixed acetabular shell, some surgeons advocate cementing a polyethylene liner into the shell when a liner exchange is not possible. So far the strength of this cement locking mechanism has been measured on only a few specimens. The purpose of this study is to correct that oversight by measuring the push-out and lever-out strengths of an acetabular polyethylene liner cemented into a porous-coated shell. We cemented acetabular liners into porous-coated acetabular shells using first-generation cementing techniques. Each of 30 specimens was tested for its push-out or lever-out strength. The results suggest that the strength of a cemented polyethylene liner locking mechanism is similar to that of an uncemented acetabular shell.