The fate of massive allografts in total hip acetabular revision surgery.

A series of 23 major load-bearing acetabular allografts done in conjunction with revision total hip arthroplasty were prospectively evaluated. This study includes cases with a minimum 2-year follow-up period. The procedures were performed using noncemented porous-coated acetabular components with pegs. In seven acetabula there was no change in cup position when compared with the initial postoperative roentgenogram (35%). Six acetabula migrated 3-5 mm during the first 2 years, then became stable without further progression (28.6%). In six cases (30%) gross loosening and migration occurred, requiring revision to a larger cup. One case required exchange arthroplasty for infection (5%). All biopsies taken at the time of the revision for failure showed viable bone replacing allograft. If the criteria for success of major superior acetabular allografts include incorporation of the graft and long-term stability of the implant, then the success rate in this series is very low. Only 7 of 20 hips were successful over a relatively short time period. However, if expectations are lowered, and the procedure is considered successful if adequate bone stock is restored to the acetabulum to allow reconstruction with a cementless cup firmly fixed in viable bone, then all but three revisions were successful.