Primary total hip arthroplasty using a dual-geometry cup to treat protrusio acetabuli.

This retrospective study examined the results of 29 total hip arthroplasties on patients with protrusio acetabuli, implanted with a dual-geometry shell with a mean follow-up of 48 months (range, 24-110). All surgeries were performed using a conical reamer in addition to a spherical reamer with morsellized autogenous graft packed into the medial acetabular protrusio defect. The Harris Hip Score increased from 41 to 85. There were no cases of aseptic loosening of the acetabular component by radiographic criteria. In 93% of the cases (27 hips), the bone graft appeared incorporated, and in 83% of the cases (24 hips), there were no radiolucent lines present. Using a 2-stage technique of bone preparation to insert a dual-geometry acetabular cup, excellent results were obtained in these 29 hips.