Teeter Matthew G, Milner Jaques S, Naudie Douglas D R, MacDonald Steven J
Division of Orthopaedic Surgery, London Health Sciences Centre, London, ON, Canada.
Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.
Knee. 2014 Aug;21(4):801-5. doi: 10.1016/j.knee.2014.04.009. Epub 2014 Apr 26.
Quantitative measurements of damage and wear in orthopaedic components retrieved from patients during revision surgery can provide valuable information. However, to perform these measurements there needs to be an estimate of the original, unworn geometry of the component, often requiring multiple scans of the various sizes of components that have been retrieved. The objective of this study was to determine whether the articular and backside surfaces could be independently segmented from a micro-CT reconstruction of a tibial insert, such that a tibial insert of one thickness could be used as a reference for a tibial insert of a different thickness.
New tibial inserts of a single width but with six different thicknesses were obtained and scanned with micro-CT. An automated method was developed to computationally segment the articular and backside surfaces of the components. Variability between intact and extracted components was determined.
The deviations between the comparisons of the extracted surfaces (range, 0.0004 to 0.010 mm) were less (p<0.001) than the baseline deviation between the intact surfaces (range, 0.0002 to 0.053 mm).
An extracted surface from one insert thickness could be used to accurately represent the surface of an insert of a different thickness. This greatly enhances the feasibility of performing retrieval studies using micro-CT as a quantitative tool, by reducing the costs and time associated with acquiring, scanning, and reconstructing multiple reference tibial insert geometries.
This will add greater detail to studies of retrieved implants, to better establish how implants are functioning in vivo.
对翻修手术中从患者体内取出的骨科植入物的损伤和磨损进行定量测量可提供有价值的信息。然而，要进行这些测量，需要估计植入物的原始未磨损几何形状，这通常需要对取出的各种尺寸的植入物进行多次扫描。本研究的目的是确定是否可以从胫骨假体的微型计算机断层扫描（micro-CT）重建中独立分割出关节面和背面，以便一种厚度的胫骨假体可以用作不同厚度胫骨假体的参考。
获取了单一宽度但具有六种不同厚度的新型胫骨假体，并进行微型计算机断层扫描。开发了一种自动化方法，通过计算分割这些部件的关节面和背面。确定完整部件和提取部件之间的变异性。
提取表面比较之间的偏差（范围为0.0004至0.010毫米）小于完整表面之间的基线偏差（范围为0.0002至0.053毫米）（p<0.001）。
从一种厚度的假体提取的表面可用于准确代表不同厚度假体的表面。通过降低获取、扫描和重建多个参考胫骨假体几何形状相关的成本和时间，这大大提高了使用微型计算机断层扫描作为定量工具进行取出研究的可行性。
这将为取出植入物的研究增添更多细节，以便更好地确定植入物在体内的功能情况。
