Revision of Total Hip Arthroplasty with Acetabular Bone Defects: Are Biological Grafts Really Better than Synthetic Bone Graft Substitutes?

Background: Acetabular aseptic loosening due to bone defect in total hip arthroplasty revisions is a great challenge and several solutions have been proposed, but a broadly accepted consensus in the literature has not been reached yet. The aim of this study is to compare the clinical and radiographic results of acetabular bone defects treatment with biological-only graft or with a mixture of bone graft substitute and biological graft. Methods: 33 patients had revision hip arthroplasty using impaction grafting with biological-only graft (21 patients, Group A) or a 1/3 mixture of allograft and tricalcium phosphate bone graft substitute (12 patients, Group B). Patients were reassessed at a minimum of one year after surgery with new x-rays and the Harris Hip Score (HHS). Results: Survivorship of bone graft was 86% in Group A and 100% in Group B at a mean follow-up of 35 months. No statistical difference between the two groups was found in terms of implants survivorship (P=0.28), clinical (P=0.08) or radiographic (P=0.27) outcomes. Conclusion: In our experience the use of tricalcium phosphate bone graft substitutes in combination with allo and autograft provides good outcomes, low risk of failure and great clinical and radiographic results. Further investigations on larger samples are needed to impact clinical practice.