LONG TERM FOLLOW-UP RESULTS FOR MINOR COLUMN ACETABULAR ALLOGRAFT IN REVISION HIP ARTHROPLASTY

Abstract

Introduction: The objective for this study was to assess the long term results for minor column allograft used in revision hip arthroplasty.

Methods: We prospectively included patients undergoing acetabular cup revision using minor column allograft with a minimum of 5 years follow-up. Minor column allograft was used in uncontained acetabular bone defects of sizes between 30% and 50% of the acetabulum. Acetabular failures requiring re-revisions at any time after surgery were included. Acetabular failure for any cause requiring re-revision surgery was used as end-point. Graft failure was considered when re-revision required the concurrent use of structural bone graft, metal augments or excision arthroplasty for any cause.

Results: There were 65 cases that met the study criteria. We included 5 deaths with a mean follow-up of 11.9 years (6.8–14.8) and 10 losses to follow-up after a mean follow-up of 11.7 years (5.3–17.4). Twenty eight acetabulum failed, with 14 occurring before 5 years at a mean of 1.8 years (0.1–4.8) and 14 occurring after 5 years at a mean of 12.2 years (5.6–23.2). Causes included aseptic loosening (23), infection (2), dislocation (1), graft non-union (1) and cup fracture (1). Fourteen grafts failed, with 8 occurring before 5 years at a mean of 1.2 years (0.5–4) and 6 occurring after 5 years at a mean of 11.3 years (6–23.2) after surgery. The mean improvement in modified Harris Hip Scores was 32.3 at 1 year and 32.6 at last follow-up assessment. The cup survivorship was 56.9 % and graft survivorship 78.5 % at a mean follow-up of 16.3 years (5.3–24.8).

Discussion: Metal augments have been used in revision arthroplasty for low demand patients but we recommend the use of minor column allografts in higher demand patients who are more likely to require further revision surgery.