Quantification of interdigitation at bone cement/cancellous bone interfaces in cemented femoral reconstructions

The mechanical interlock created at the cement/cancellous bone interface in cemented femoral reconstructions is crucial to the longevity of the replacement. To accurately model the mechanics of the interface, its morphological features must be quantified. This paper applies a semiautomated procedure to the analysis of the cement/bone interdigitation characteristics of six cemented femora: two which have been prepared in vivo and later retrieved, and four which were prepared bz vitro. A parameter which combines the undulations of the cement/bone interface in a transverse slice into one value, is used to explore the trends in the interlock along the length of the femur. The differences in the interdigitation produced in the in vivo and in vitro groups are also explored.