Reconstruction of Segmental Defects: Onlay Allografting

Abstract

Successive total hip revisions are associated with loss of bone stock, and revision for loosening of one hip component is associated with an increased rate of subsequent loosening of that same component.^1–4 Stromberg and Herberts⁴ attributed the poor results they found in a 10-year follow-up study of revision total hip arthroplasty in young patients (ie, younger than 55 years of age) to poor bone quality at the time of revision. Callaghan et a1.¹ also found that mechanical failure and progressive radiolucencies in revision hip arthroplasties correlated significantly with poor-quality bone stock of the preoperative femur. Femoral bone loss—in the form of osteolytic defects, cortical windows, and perforations—has been associated with stem breakage,⁵ femoral fracture,^6,7 femoral subsidence,⁸ and femoral loosening.⁹ At the extreme, loss of femoral bone stock can preclude prosthesis reimplantation,^3,10 but any loss of bone means some loss of implant bone support.