Delft University of Technology, Quantitative Imaging, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
J Biomech. 2010 May 28;43(8):1463-9. doi: 10.1016/j.jbiomech.2010.02.006. Epub 2010 Feb 24.
Diagnosing of injuries of the wrist bones is problematic due to a highly complex and variable geometry. knowledge of variations of healthy bone shapes is essential to detect wrist pathologies, developing prosthetics and investigating biomechanical properties of the wrist joint. In previous literature various methods have been proposed to classify different scaphoid and lunate types. These classifications were mainly qualitative or were based on a limited number of manually determined surface points. The purposes of this study are to develop a quantitative, standardized description of the variations in the scaphoid and lunate and to investigate whether it is feasible to divide carpal bones in isolated shape categories based on statistical grounds. The shape variations of the scaphoid and lunate were described by constructing a statistical shape model (SSM) of healthy bones. SSM shape parameters were determined that describe the deviation of each shape from the mean shape. The first five modes of variation in the SSMs describe 60% of the total variance of the scaphoid and 57% of the lunate. Higher modes describe less than 5% of the variance per mode. The distributions of the parameters that characterize the bone shape variations along the modes do not significantly differ from a normal distribution. The SSM provides a description of possible shape variations and the distribution of scaphoid and lunate shapes in our population at an accuracy of approximately the voxel size (0.3x0.3x0.3mm(3)). The developed statistical shape model represents the previously qualitatively described variations of scaphoid and lunate. However, strict classifications based on shape differences are not feasible on statistical grounds.
由于手腕骨骼的高度复杂和多变的几何形状，对手腕骨骼损伤的诊断存在问题。了解健康骨骼形状的变化对于检测手腕病变、开发假肢以及研究手腕关节的生物力学特性至关重要。在之前的文献中，已经提出了各种方法来对不同的舟骨和月骨类型进行分类。这些分类主要是定性的，或者是基于有限数量的手动确定的表面点。本研究的目的是开发一种对舟骨和月骨变化的定量、标准化描述，并研究是否可以基于统计学依据将腕骨分为独立的形状类别。通过构建健康骨骼的统计形状模型 (SSM) 来描述舟骨和月骨的形状变化。确定了 SSM 形状参数，这些参数描述了每个形状与平均形状的偏差。SSM 中的前五个变化模式描述了舟骨总方差的 60%和月骨的 57%。更高的模式每模式描述的方差小于 5%。沿模式描述骨骼形状变化的参数分布与正态分布没有显著差异。SSM 以大约体素大小（0.3x0.3x0.3mm(3)）的精度提供了对手腕骨骼形状变化和我们人群中舟骨和月骨形状分布的描述。所开发的统计形状模型代表了之前定性描述的舟骨和月骨的变化。然而，基于形状差异的严格分类在统计学上是不可行的。
