Haffner-Luntzer Melanie, Liedert Astrid, Ignatius Anita
Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany.
Innov Surg Sci. 2016 Dec 3;1(2):57-63. doi: 10.1515/iss-2016-0021. eCollection 2016 Dec.
Bone can adapt to changing load demands by mechanically regulated bone remodeling. Osteocytes, osteoblasts, and mesenchymal stem cells are mechanosensitive and respond to mechanical signals through the activation of specific molecular signaling pathways. The process of bone regeneration after fracture is similarly and highly regulated by the biomechanical environment at the fracture site. Depending on the tissue strains, mesenchymal cells differentiate into fibroblasts, chondrocytes, or osteoblasts, determining the course and the success of healing. In the aged organism, mechanotransduction in both intact and fractured bones may be altered due to changed hormone levels and expression of growth factors and other signaling molecules. It is proposed that altered mechanotransduction may contribute to disturbed healing in aged patients. This review explains the basic principles of mechanotransduction in the bone and the fracture callus and summarizes the current knowledge on aging-induced changes in mechanobiology. Furthermore, the methods for external biomechanical stimulation of intact and fractured bones are discussed with respect to a possible application in the elderly patient.
骨骼可通过机械调节的骨重塑来适应不断变化的负荷需求。骨细胞、成骨细胞和间充质干细胞具有机械敏感性，并通过激活特定的分子信号通路对机械信号作出反应。骨折后的骨再生过程同样受到骨折部位生物力学环境的高度调节。根据组织应变情况，间充质细胞可分化为成纤维细胞、软骨细胞或成骨细胞，从而决定愈合的进程和成功与否。在老年机体中，由于激素水平的变化以及生长因子和其他信号分子表达的改变，完整骨骼和骨折骨骼中的机械转导可能会发生改变。有人提出，机械转导的改变可能导致老年患者愈合障碍。本文综述解释了骨骼和骨折骨痂中机械转导的基本原理，并总结了目前关于衰老引起的力学生物学变化的知识。此外，还讨论了对完整骨骼和骨折骨骼进行外部生物力学刺激的方法及其在老年患者中的可能应用。
