Allografts promote skeletal regeneration of periprosthetic femoral bone loss.

Background: Periprosthetic bone loss is a common clinical problem in hip arthroplasty that must be addressed during revision surgery to achieve adequate implant stability. Although bone allografts represent the clinical standard among substitute materials used, evidence of their regenerative potential at the microstructural, cellular, and compositional level is lacking. Methods: A multiscale imaging approach comprising contact radiography, undecalcified histology, scanning electron microscopy, and nanoindentation was employed on human femoral explants obtained postmortem many years after allograft use during revision surgery. Results: The degree of skeletal regeneration through allograft incorporation between host bone and allograft bone was highly dependent on the defect depth (R Conclusion: This is the first multiscale, histomorphometry-based evaluation of bone allografts used in revision hip arthroplasty for femoral bone loss in humans, demonstrating that they adequately facilitate skeletal regeneration through osteoconduction and subsequent remodelling. The translational potential of this article: This study identified the mechanisms and determinants of femoral defect regeneration through allografts on the basis of a unique sample collection. While our results support their favourable clinical outcomes, the scientific basis for incomplete incorporation is also demonstrated.