Noncemented acetabular revision arthroplasty using allograft bone.

The authors retrospectively reviewed a series of 106 acetabular revisions for failed cemented total hip arthroplasties followed from 12 to 56 months. All of the sockets had extensive bone deficiency requiring bone graft surgery. The deficiencies were classified as cavitary, combined cavitary and segmental, and pelvic discontinuity. The purpose was to evaluate clinical experience with three different acetabular components. In chronological order, the three components tested were bipolar type, truncated-cone screw-in type, and porous-coated titanium press-fit type with fins. These were combined with four different bone augmentation constructs, using nonstructural morselized fresh-frozen allograft or segmental freeze-dried allograft. Follow-up evaluation of both the bipolar and screw-in designs showed frequent migration with bone graft resorption, compromising the clinical scores and leading to some revisions. The press-fit design had little migration, reliable graft healing, and better clinical scores. No revisions have been done. The nonstructural morselized bone allograft fared better under stable cups. The large segmental grafts did much better when buttress plating was combined with interfragmentary screw fixation compared to screws alone.