Long term results of impaction Bone grafting using a synthetic graft (Apapore) in revision hip surgery.

Introduction: Impaction Bone grafting (IBG) in Revision THR is challenging and places demands on allograft stores. Identifying a potential synthetic replacement that works in the longer term was the aim of this study.

Methods: We retrospectively reviewed 21 sequential patients who had undergone revision THR using IBG. They were randomised to receive either combined allograft and synthetic graft or Allograft alone. Among the surviving 15 patients, there were total of 25 procedures were carried out. 15 hips underwent IBG in the acetabulum and 10 hips underwent femoral IBG. Eight patients received a 50/50 mixture of allograft and synthetic Bone graft (Apapore) and seven allograft alone. Bone loss was classified using Paprosky classification. The average follow up was 10 years.

Results: Of the 21 patients, 6 had died of unrelated causes and were excluded. There were 3 re-operations but no revision of the original components. There was no significant implant migration detected. 3 acetabular components had confluent lucent lines in zone-1 which remained stable on long term follow up. 2 patients sustained femoral peri-prosthetic fractures after a simple fall and one patient who developed deep infection treated by DAIR. The modified oxford hip score post-operatively was 18 in allograft group and 22 in Apapore group.

Conclusion: Long-term results indicate that the combined use of synthetic graft in Impaction Bone grafting is an effective substitute.