Gillard Faye C, Dickinson Alexander S, Schneider Urs, Taylor Andrew C, Browne Martin
Bioengineering Science Research Group, University of Southampton, Southampton, UK.
Proc Inst Mech Eng H. 2013 Dec;227(12):1255-64. doi: 10.1177/0954411913500265. Epub 2013 Aug 21.
The shape of the acetabular cartilage follows the contact stress distribution across the joint. Accurate characterisation of this geometry may be useful for the development of acetabular cup devices that are more biomechanically compliant. In this study, the geometry of the acetabular cartilage was characterised by taking plaster moulds of the acetabulum from 24 dry bone human pelvises and digitising the mould shapes using a three-dimensional laser scanner. The articular bone surface geometry was analysed, and the shape of the acetabulum was approximated by fitting a best-fit sphere. To test the hypothesis that the acetabulum is non-spherical, a best-fit ellipsoid was also fitted to the geometry. In each case, points around the acetabular notch edge that disclosed the articular surface geometry were identified, and vectors were drawn between these and the best-fit sphere or ellipsoid centre. The significantly larger z radii (into the pole) of the ellipsoids indicated that the acetabulum was non-spherical and could imply that the kinematics of the hip joint is more complex than purely rotational motion, and the traditional ball-and-socket replacement may need to be updated to reflect this motion. The acetabular notch edges were observed to be curved, with males exhibiting deeper, wider and shorter notches than females, although the difference was not statistically significant (mean: p = 0.30) and supports the use of non-gender-specific models in anatomical studies.
髋臼软骨的形状遵循整个关节的接触应力分布。准确描述这种几何形状可能有助于开发在生物力学上更贴合的髋臼杯装置。在本研究中，通过从24个干燥的人体骨盆髋臼制作石膏模型，并使用三维激光扫描仪对模型形状进行数字化处理，来描述髋臼软骨的几何形状。分析关节骨表面几何形状，并通过拟合最佳拟合球体来近似髋臼的形状。为了检验髋臼不是球形的假设，还对几何形状拟合了最佳拟合椭球体。在每种情况下，确定髋臼切迹边缘周围揭示关节表面几何形状的点，并在这些点与最佳拟合球体或椭球体中心之间绘制向量。椭球体明显更大的z半径（朝向极点）表明髋臼不是球形的，这可能意味着髋关节的运动学比单纯的旋转运动更复杂，传统的球窝置换可能需要更新以反映这种运动。观察到髋臼切迹边缘是弯曲的，男性的切迹比女性更深、更宽且更短，尽管差异无统计学意义（均值：p = 0.30），这支持在解剖学研究中使用非性别特异性模型。
