Augmentation of peri-implant bone improves implant stability: Quantification using simulated bone loss

Low bone quality, such as induced by osteoporosis, is considered a main factor leading to failure of fracture fixations. Peri-implant bone augmentation has been proposed as a means of reducing failure rates in osteoporotic bone by improving implant stability. The beneficial effects of pharmacological augmentation of bone in the immediate vicinity of the implant have been demonstrated. Yet, a quantitative understanding of the role of peri-implant bone in implant stability is lacking. Therefore, the aim of our study was to quantify the effects of bone loss and peri-implant bone augmentation on implant stability using image-based finite element analyses. Using a validated model, we simulated how osteoporotic bone loss would affect implant stability in human humeral heads. We also quantified how augmentation of peri-implant bone can enhance implant stability. Our simulations revealed that a 30% reduction in bone mass led to a 50% decrease in implant stability. We also found that peri-implant bone augmentation increased implant stability and that the efficiency of bone augmentation decreased with increasing peri-implant distance. These findings highlight the strong effect that bone loss has on implant fixation and the potential of peri-implant bone augmentation for improving implant anchorage in low quality bone. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:178–184, 2012