Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
J Biomech. 2013 Mar 15;46(5):941-8. doi: 10.1016/j.jbiomech.2012.12.012. Epub 2013 Jan 16.
Patient-specific simulations of bone remodelling could enable predicting how bone micro-structural integrity would be affected by bone diseases, drugs or other factors, and, ultimately could help clinicians to improve their prognoses. To simulate load-adaptive remodelling, however, knowledge about the physiological external loading acting on the bone is required. Assuming that load adaptation leads to homogeneous tissue loading, we previously developed a method to estimate the physiological loading history from bone micro-structural morphology. We were able to reconstruct the loading history of a simple load case that was applied in an animal experiment. However, we found considerable inhomogeneity in tissue loading suggesting that the bones were not fully adapted. Also, we noted differences in bone micro-architecture between animals despite common loading history, possibly due to differences caused by the stochastic nature of the bone remodelling process. In the present study, we aim at validating the load estimation algorithm in a well-controlled environment in which more complicated loading conditions are applied. Specifically, we want to test its accuracy for partially and fully developed bone structures and for differences in bone micro-architectures as they can occur due to stochastic events, even for bones with a common loading history. This was possible by using synthetic micro-architectures obtained from bone remodelling simulations as the basis for our load estimation algorithm. Loading histories based on fully adapted structures were predicted with a maximum error of 4.4% and predictions were not affected by differences in bone micro-architecture. These results show that our load estimation algorithm produces reasonable predictions and might be a suitable tool to define in vivo loading for patient-specific bone remodelling studies.
骨重建的个体化模拟可以预测骨疾病、药物或其他因素对骨微观结构完整性的影响，并最终帮助临床医生改善预后。然而，要模拟负载适应性重建，需要了解作用于骨骼的生理外部载荷。假设负载适应会导致组织均匀加载，我们之前开发了一种从骨微观结构形态估计生理加载历史的方法。我们能够重建在动物实验中应用的简单加载情况的加载历史。然而，我们发现组织加载存在相当大的不均匀性，表明骨骼没有完全适应。此外，尽管有共同的加载历史，但我们注意到动物之间的骨微观结构存在差异，这可能是由于骨骼重塑过程的随机性造成的差异。在本研究中，我们旨在在一个控制良好的环境中验证负载估计算法，该环境中应用了更复杂的加载条件。具体来说，我们希望测试其在部分和完全发育的骨骼结构以及由于随机事件导致的骨微观结构差异方面的准确性，即使对于具有共同加载历史的骨骼也是如此。这是通过使用从骨骼重塑模拟中获得的合成微观结构作为我们的负载估计算法的基础来实现的。基于完全适应结构的加载历史的预测最大误差为 4.4%，并且预测不受骨微观结构差异的影响。这些结果表明，我们的负载估计算法产生了合理的预测结果，可能是定义个体化骨骼重塑研究中体内负载的合适工具。
