Pull-out strengths of bone screws at various sites about the pelvis--a preliminary study.

The pull-out strength of both cortical and cancellous screws from bone at various sites about cadaveric pelves was examined. No significant differences were seen between cortical or cancellous screws at similar sites with the possible exception of the sacroiliac joint. Pull-out strengths were best correlated to the depth of bone at a particular screw hole. For practical purposes, the strongest sites are in the thick buttress of bone along the iliopubic column.