2- to 10-year follow-up study of acetabular revisions using allograft bone to repair bone defects

The failure rates of revision of acetabular components have been high; however, long-term success has been reported with the use of particulate allografts or autografts with large-diameter prosthetic cups to correct bone deficiencies when host-cup contact is al least 30% to 50%. The purpose of this study was to review 2- to 10-year follow-up data on complex acetabular revisions in which contact between allograft bone and the prosthetic cup was at least 50%. In the 47 hips monitored clinically and radiographically for a mean of 5 years, results were classified as excellent in 37%, good in 26%, fair in 17%, and poor in 19%. The mean Harris hip score was 82.5 (range, 39-100). The prosthetic cups migrated in 3 hips, but 2 stabilized within 1 year. Three cups had complete radiolucent lines without migration; the lines did not correlate with location of the allografts. Although bone ingrowth into porous surfaces from allografts is debatable, the results of the study show that massive allograft reconstruction of the acetabulum can provide both immediate and long-term stability of the prosthetic cup and restore bone stock.