A tibial-based coordinate system for three-dimensional data
A tibial-based coordinate system for three-dimensional data
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DOI：
10.1016/j.knee.2006.11.001
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发表时间：
2007-03-01
期刊：
影响因子：
1.9
通讯作者：
Lee, Jordan
中科院分区：
文献类型：
--
作者：
Fitzpatrick, Clare;FitzPatnick, David;Lee, Jordan
一个精确和可重复的胫骨测量系统将有助于胫骨几何形状的定义和改善胫骨假体的设计。与股骨不同，构建胫骨坐标框架没有标准化的方法。大多数胫骨测量是相对于股骨轴或CT/MRI扫描仪或x光机的坐标框架给出的。本研究的目的是建立一个独立的胫骨坐标框架。数据包括来自34名受试者的CT扫描。选择胫骨解剖轴作为轴向。选择与胫骨轴外侧面平行并与解剖轴正交的前后轴，由此可导出中外侧轴。选择的AP轴与手术胫骨AP轴进行比较，测量其相对于共同轴，即胫骨后髁线（PTCL）的变异性。所选AP轴与PTCL垂直方向的平均夹角为-4.07度，标准差为4.28度。手术AP轴与PTCL垂直方向的平均夹角为- 18.56度，标准差为4.66度。两组测量值的方差无显著差异（p=0.63）。当通过对准虚拟切除剖面独立于PTCL参考轴测量时，所选AP轴的变异性甚至更小（标准偏差2.74度）。解剖上，选择的AP轴几乎垂直于胫骨后髁轴。该坐标系统有助于收集一致和可重复的人体测量数据，可用于改进胫骨植入物的设计，并且可以结合基于CT/MR图像的计算机辅助手术，作为TKR中胫骨部件定位的指导。(c) 2006 Elsevier B.V.版权所有
An accurate and repeatable tibial measurement system will aid in the definition of tibial geometry and improving tibial prosthesis design. Unlike in the femur, there is no standardized method for constructing a tibial coordinate frame. Most tibial measurements are given relative to femoral axes or the coordinate frame of the CT/MRI scanner or radiograph machine. The objective of this study was to establish an independent tibial coordinate frame. Data consisted of CT scans from 34 subjects. The tibial anatomical axis was chosen as the axial axis. The anteroposterior (AP) axis was selected to be parallel to the lateral surface of the tibial shaft and orthogonal to the anatomical axis and from this the mediolateral axis could be derived. The selected AP axis was compared with the surgical tibial AP axis by measuring their variability relative to a common axis, the posterior tibial condylar line (PTCL). The mean angle between the selected AP axis and the perpendicular to the PTCL was measured as -4.07 degrees, standard deviation of 4.28 degrees. The mean angle between the surgical AP axis and the perpendicular to the PTCL was measured as - 18.56 degrees, standard deviation of 4.66 degrees. There was no significant difference in the variance of the two sets of measurements (p=0.63). Variability of the selected AP axis was even smaller (standard deviation of 2.74 degrees) when measured independently from the PTCL reference axis, by aligning virtual resection profiles. Anatomically, the selected AP axis was almost perpendicular to the posterior tibial condylar axis. This coordinate system can aid in gathering consistent and repeatable anthropometric data that can be used to improve tibial implant design and could also, in combination with CT/MR imaged-based computer assisted surgery, be used as a guideline for tibial component positioning in TKR. (c) 2006 Elsevier B.V. All rights reserved.