Department of Sport and Human Movement Science, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria; Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria; Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences, University of Vienna, Vienna, Austria.
Department of Sport and Human Movement Science, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria; Neuromechanics Research Group, Centre for Sport Science and University Sports, University of Vienna, Vienna, Austria.
Gait Posture. 2024 Sep;113:158-166. doi: 10.1016/j.gaitpost.2024.06.012. Epub 2024 Jun 18.
Femoral deformities are highly prevalent in children with cerebral palsy (CP) and can have a severe impact on patients' gait abilities. While the mechanical stress regime within the distal femoral growth plate remains underexplored, understanding it is crucial given bone's adaptive response to mechanical stimuli. We quantified stresses at the distal femoral growth plate to deepen our understanding of the relationship between healthy and pathological gait patterns, internal loading, and femoral growth patterns.
This study included three-dimensional motion capture data and magnetic resonance images of 13 typically developing children and twelve participants with cerebral palsy. Employing a multi-scale mechanobiological approach, integrating musculoskeletal simulations and subject-specific finite element analysis, we investigated the orientation of the distal femoral growth plate and the stresses within it. Limbs of participants with CP were grouped depending on their knee flexion kinematics during stance phase as this potentially changes the stresses induced by knee and patellofemoral joint contact forces.
Despite similar growth plate orientation across groups, significant differences were observed in the shape and distribution of growth values. Higher growth rates were noted in the anterior compartment in CP limbs with high knee flexion while CP limbs with normal knee flexion showed high similarity to the group of healthy participants.
Results indicate that the knee flexion angle during the stance phase is of high relevance for typical bone growth at the distal femur. The evaluated growth rates reveal plausible results, as long-term promoted growth in the anterior compartment leads to anterior bending of the femur which was confirmed for the group with high knee flexion through analyses of the femoral geometry. The framework for these multi-scale simulations has been made accessible on GitHub, empowering peers to conduct similar mechanobiological studies. Advancing our understanding of femoral bone development could ultimately support clinical decision-making.
脑瘫（CP）患儿中股骨畸形非常普遍，严重影响患者的步态能力。虽然股骨远端生长板的力学应力状态仍未得到充分探索，但鉴于骨骼对机械刺激的适应性反应，理解这一点至关重要。我们对股骨远端生长板的应力进行了量化，以深入了解健康和病理步态模式、内部负荷和股骨生长模式之间的关系。
本研究包括 13 名正常发育儿童和 12 名脑瘫患者的三维运动捕捉数据和磁共振图像。采用多尺度机械生物学方法，结合肌肉骨骼模拟和基于个体的有限元分析，我们研究了股骨远端生长板的方向和内部的应力。根据 CP 患者在站立阶段的膝关节屈曲运动学将 CP 患者的肢体分组，因为这可能会改变膝关节和髌股关节接触力引起的应力。
尽管两组的生长板方向相似，但生长值的形状和分布存在显著差异。在膝关节高度屈曲的 CP 肢体中，前室的生长速度较高，而膝关节正常屈曲的 CP 肢体与健康组的相似性很高。
结果表明，站立阶段的膝关节屈曲角度对股骨远端的典型骨骼生长具有重要意义。评估的生长率显示出合理的结果，因为前室的长期促进生长导致股骨的前向弯曲，这通过对股骨几何形状的分析得到了高度屈曲膝关节组的证实。这些多尺度模拟的框架已在 GitHub 上提供，使同行能够进行类似的机械生物学研究。深入了解股骨骨发育最终可以支持临床决策。
