Case Western Reserve University, Department of Mechanical and Aerospace Engineering, 2123 Martin Luther King Jr Dr, Cleveland, OH, 44106, USA.
J Mech Behav Biomed Mater. 2022 Jan;125:104889. doi: 10.1016/j.jmbbm.2021.104889. Epub 2021 Oct 8.
The whole bone geometry, microstructure, and mechanical properties of mature human bone are widely reported; however, immature bone (0-18 years) has not been similarly robustly characterized. There is an interest in analyzing and predicting the mechanical loading conditions associated with long bone diaphyseal fractures attributed to trauma in children. Thus, understanding the mechanical properties of immature bone in a temporal reference frame is an essential first step to understand diaphyseal fractures of pediatric long bones. The purpose of this systematic review was to ask, what is the state of knowledge regarding the 1) evolution of whole bone geometry and microstructure of immature pediatric bone as a function of maturation and 2) cortical bone density and experimental quasi-static mechanical properties at the tissue level in the diaphyseal region of immature pediatric long bones? The systematic search yielded 36 studies of the whole bone geometry, microstructure, and mechanical properties of immature pediatric long bones. The elastic modulus, yield stress, and ultimate stress were shown to generally increase with maturation, whereas the yield strain was approximately invariant; however, the specific year-to-year progression of these properties could not be characterized from the limited studies available. The results of this systematic search indicate there is a dearth of knowledge associated with the biomechanics of cortical bone from immature pediatric long bones; it also provides a basis for computational studies of immature human long bones. Additional biomechanical studies of immature human bone are necessary to develop a robust catalogue, which can be used in broad applications to understand fracture mechanics, bone pathologies, and athletic injury in the pediatric setting.
成熟人体骨骼的整体几何形状、微观结构和力学性能已被广泛报道；然而，尚未对不成熟骨骼（0-18 岁）进行类似的全面描述。人们对分析和预测与儿童创伤相关的长骨干骺端骨折的力学加载条件很感兴趣。因此，了解儿童长骨骨干骨折的力学性能是理解不成熟骨骼在时间参考框架内的机械性能的重要第一步。本系统综述旨在提出以下问题：1）成熟过程中不成熟儿童骨骼的整体骨骼几何形状和微观结构的演变情况如何；2）在不成熟儿童长骨干骺端区域的组织水平上，皮质骨密度和实验准静态力学性能的演变情况如何？系统检索共获得 36 项关于不成熟儿童长骨整体骨骼几何形状、微观结构和力学性能的研究。结果表明，弹性模量、屈服应力和极限应力通常随成熟度的增加而增加，而屈服应变大致不变；然而，从现有的有限研究中，无法描述这些特性的具体逐年变化情况。本系统检索的结果表明，有关不成熟儿童长骨皮质骨生物力学的知识匮乏；这也为不成熟人类长骨的计算研究提供了基础。需要对不成熟人类骨骼进行更多的生物力学研究，以开发一个可以广泛应用于理解儿科骨折力学、骨骼病理学和运动损伤的稳健目录。
