Akman Alp, Demirkan Ahmet Fahir, Akkoyunlu Nuran Sabir
Department of Orthopedics and Traumatology, Faculty of Medicine Hospital, Pamukkale University, Denizli, Turkey.
Jt Dis Relat Surg. 2020;31(1):14-9. doi: 10.5606/ehc.2020.65258.
This study aims to investigate if geometrical modelling in addition to three-dimensional (3D) modelling will standardize models and allow performing mathematical calculations easily for the compatibility of femoral implant curvature.
The study included 50 subjects (27 males, 23 females; mean age 55 years; range, 21 to 84 years). The femoral shaft intramedullary cavity was resembled into a chord of the ring cyclide, where the rotational radius was centered at its smallest radius. A 3D evaluation of the left femoral computed tomography data of the subjects was used to investigate the population parameters. The fitting was defined as being between the anterior and posterior border radii in the sagittal plane.
The best fitting radius of implants was in between 90 to 99 cm in 72% of subjects in our sample. These radii values were lower than the mean intramedullary and cortical centerline radii which had only 62% and 50% fittings, respectively, among our population sample. The bowing radii and the smallest intramedullary width increased with the femoral length. These values were not affected by gender.
This modelling may have value for understanding femoral shaft intramedullary cavity geometry and may be a good tool to assess implant fitting.
本研究旨在调查除三维（3D）建模外，几何建模是否会使模型标准化，并便于进行数学计算以实现股骨植入物曲率的兼容性。
该研究纳入了50名受试者（27名男性，23名女性；平均年龄55岁；范围为21至84岁）。股骨干髓腔内被模拟为环面的一条弦，其旋转半径以最小半径为中心。利用受试者左股骨计算机断层扫描数据进行三维评估，以研究总体参数。拟合定义为矢状面内前后缘半径之间的情况。
在我们的样本中，72%的受试者植入物的最佳拟合半径在90至99厘米之间。这些半径值低于平均髓内半径和皮质中心线半径，在我们的总体样本中，它们的拟合率分别仅为62%和50%。弯曲半径和最小髓内宽度随股骨长度增加。这些值不受性别的影响。
这种建模对于理解股骨干髓腔几何形状可能具有价值，并且可能是评估植入物拟合的良好工具。
