REVISION OF THE ACETABULAR COMPONENT OF A TOTAL HIP-ARTHROPLASTY WITHA MASSIVE STRUCTURAL ALLOGRAFT - STUDY WITH A MINIMUM 5-YEAR FOLLOW-UP

The results of the placement of a massive structural acetabular allogr aft in conjunction with a revision total hip arthroplasty in thirty-tw o patients (thirty-three hips) were evaluated at a minimum of five yea rs. The graft supported more than 50 per cent of the cup in all of the patients, The goals of a revision operation in a hip that has massive loss of bone are to provide support for the cup, to approximate the n ormal anatomy, to restore the length of the lower limb, and to restore bone stock should a future revision be necessary. Clinical and radiog raphic review at an average of seven years (range, five to eleven year s) after the revision revealed that eighteen hips had needed no additi onal operation, seven hips had needed a repeat revision but the struct ural allograft was intact and had been used to support the cup at the repeat revision, and eight hips had had failure of both the prosthesis and the allograft, The result was considered a clinical and radiograp hic success when the hip score had increased at least 20 points, the c up was stable, the allograft had united, and no additional operation w as necessary, According to these criteria, the rate of success was 55 per cent (eighteen of thirty-three hips), The only factor that was fou nd to be clinically important with respect to outcome was the method o f reconstruction, Seven of the eight hips that had been reconstructed with use of a roof-reinforcement ring and a structural allograft had a successful result at an average of 7.5 years (range, five to eleven y ears). The findings of the present study support the use of a structur al allograft in the presence of massive loss of bone in order to achie ve the goals of a revision hip replacement, Because of the high rate o f success ,vith acetabular reinforcement rings, we now use this method of reconstruction whenever a massive allograft is employed on the ace tabular side.