Proximal femoral deformities can result from altered hip joint loading patterns during growth. The growth plate hyaline cartilage has low resistance to shear stress. Therefore, we hypothesized that the growth plate orients in a direction which minimizes the shear stress on its surface. A finite element model of the proximal femur was generated with a simplified flat growth plate. Hip joint forces were estimated for standing upright and standing in hip flexion. We also parametrically studied the effects of posteriorly and laterally directed loads. An algorithm was developed to predict the shape of the femoral growth plate in a plane of minimum shear (along the principal stress vectors). To characterize and compare the growth plate shapes, we represented the distance from the growth plate to a reference plane as a two-dimensional contour plot, providing information of shape and orientation across the entire surface. We also assessed the clinical measures of growth plate shape to compare our predicted growth plates with previous clinical studies data. The shape of the growth plate predicted for an upright standing load correlated closely with morphological properties of the growth plane of a typically developing child. The shape of the growth plate predicted for femoral hip flexion force was similar to the growth plate in subjects with cam morphology, a hip shape that has documented growth plate changes. The model proposed here allows for investigation of the relation between joint forces and growth plate shape, which will help predict the development of bony deformities.

中文翻译：

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通过改变髋关节负荷来预测生长板的方向：凸轮形态的潜在原因。

股骨近端畸形可能是由于生长过程中髋关节负荷模式改变而引起的。生长板透明软骨对剪切应力的抵抗力低。因此，我们假设生长板的定向方向应使其表面的剪切应力最小。用简化的平板状生长板生成股骨近端的有限元模型。估计髋关节力量可直立和屈曲。我们还从参数上研究了后向和侧向载荷的影响。开发了一种算法来预测股骨生长板在最小剪切平面（以及主应力向量）中的形状。为了表征和比较生长板的形状，我们将生长板到参考平面的距离表示为二维轮廓图，提供整个表面的形状和方向信息。我们还评估了生长板形状的临床指标，以将我们预测的生长板与先前的临床研究数据进行比较。预计竖立站立负荷的生长板形状与典型发育儿童的生长平面的形态特性密切相关。预测股骨髋关节屈曲力的生长板的形状类似于具有凸轮形态的受试者的生长板，该髋部形状已证明了生长板的变化。这里提出的模型允许研究关节力和生长板形状之间的关系，这将有助于预测骨畸形的发展。我们还评估了生长板形状的临床指标，以将我们预测的生长板与先前的临床研究数据进行比较。预计竖立站立负荷的生长板形状与典型发育儿童的生长平面的形态特性密切相关。预测股骨髋关节屈曲力的生长板的形状类似于具有凸轮形态的受试者的生长板，该髋部形状已证明了生长板的变化。这里提出的模型允许研究关节力和生长板形状之间的关系，这将有助于预测骨畸形的发展。我们还评估了生长板形状的临床指标，以将我们预测的生长板与先前的临床研究数据进行比较。预计竖立站立负荷的生长板形状与典型发育儿童的生长平面的形态特性密切相关。预测股骨髋关节屈曲力的生长板的形状类似于具有凸轮形态的受试者的生长板，该髋部形状已证明了生长板的变化。这里提出的模型允许研究关节力和生长板形状之间的关系，这将有助于预测骨畸形的发展。预计竖立站立负荷的生长板形状与典型发育儿童的生长平面的形态特性密切相关。预测股骨髋关节屈曲力的生长板的形状类似于具有凸轮形态的受试者的生长板，该髋部形状已证明了生长板的变化。这里提出的模型允许研究关节力和生长板形状之间的关系，这将有助于预测骨畸形的发展。预计竖立站立负荷的生长板形状与典型发育儿童的生长平面的形态特性密切相关。预测股骨髋关节屈曲力的生长板的形状类似于具有凸轮形态的受试者的生长板，该髋部形状已证明了生长板的变化。这里提出的模型允许研究关节力和生长板形状之间的关系，这将有助于预测骨畸形的发展。