Safe screw placement in acetabular revision surgery.

Revision of an acetabular component with extensive bone loss is a procedure that sometimes includes allografting or the placement of an unusually sized or positioned uncemented acetabular component. We evaluated the quadrant system used to guide screw placement in primary uncemented total hip surgery in the high hip center, jumbo component, and 3 designs of reinforcement rings. We used 14 pairs of cadaver hemipelves, which were prepared by removing all soft tissues except the medial neurovascular structures. With each implant, all screw holes were tested to determine if they followed the safe quadrant recommendations. In the high hip center, the center and anterior of the superoposterior quadrant was dangerous. All of the other implants met the quadrant recommendations.