Do bone properties affect loosening of half-pin external fixators at the pin-bone interface?
We successfully simulate half-pin loosening at the bone-implant interface which has been found to occur clinically. Yielding across the full cortical thickness may explain the poor performance of these devices for old-aged cases. The models are able to identify patients particularly at risk of half-pin loosening, who may benefit from alternative fixator configurations or techniques such as those using pre-tensioned fine wires.
Evidence from this analysis provides support for hypotheses predicted by identity theory, highlights the importance of examining giving and receiving support net of the other, and suggests that it is often better for the well-being of older adults to give than to receive.