School of Biomedical Engineering, Western University, 1151 Richmond St, London, ON N6A 3K7, Canada; Roth McFarlane Hand and Upper Limb Centre, St Joseph's Health Care London, 268 Grosvenor St, London, ON N6A 4V2, Canada.
Roth McFarlane Hand and Upper Limb Centre, St Joseph's Health Care London, 268 Grosvenor St, London, ON N6A 4V2, Canada; Graduate Program of Health and Rehabilitation Science, Western University, 1151 Richmond St, London, ON N6A 3K7, Canada.
J Biomech Eng. 2021 Jun 1;143(6). doi: 10.1115/1.4050129.
Delayed diagnosis of dynamic carpal instability often occurs because early changes in bone alignment and movement are difficult to detect and manifest mainly during a dynamic/functional task. Current diagnostic tools are only able to examine the carpal bones under static or sequential-static conditions. Four-dimensional (three dimensions + time) computed tomography (4DCT) enables quantification of carpal mechanics through 3D volume sequences of the wrist in motion. A comprehensive understanding of carpal mechanics is needed to define normal function and structure and provide targets for treatment of carpal injuries. In this study, measurements of scaphoid translation and joint congruency were taken by creating models from the CT scans of the carpals in extreme frames of motion, registering those models to the neutral position, transforming the models into a local coordinate system, and using software to calculate the joint surface areas (JSA). Results indicated that the centroid of the scaphoid translated 6.4 ± 1.3 mm and extended from extreme radial to extreme ulnar deviation. Results are consistent with the literature. An additional study was performed to measure the responsiveness of the 4DCT technique presented. Bone models from each frame of motion for radio ulnar deviation (RUD) and flexion extension (FE) were created and distinct differences between their JSA were measured qualitatively and quantitatively. The results show that there was statistically significantly different JSA within carpal joints between RUD and FE. These studies provide the first step in developing the methodology when using 4DCT scanning to measure subtle abnormalities in the wrist.
腕部动态不稳的延迟诊断通常是由于早期的骨骼对线和运动变化很难被察觉，主要在动态/功能任务中表现出来。目前的诊断工具只能在静态或顺序静态条件下检查腕骨。四维（三维+时间）计算机断层扫描（4DCT）能够通过运动中的腕部三维容积序列来量化腕骨力学。为了定义正常的功能和结构，并为腕骨损伤的治疗提供目标，需要全面了解腕骨力学。在这项研究中，通过在极端运动状态下创建腕骨 CT 扫描的模型，测量了舟骨的平移和关节吻合度，将这些模型注册到中立位置，将模型转换到局部坐标系，并使用软件计算关节表面积（JSA）。结果表明，舟骨的质心平移了 6.4±1.3mm，并从极度桡侧延伸到极度尺侧。结果与文献一致。还进行了一项额外的研究来测量所提出的 4DCT 技术的响应性。为桡尺偏（RUD）和屈伸（FE）的每个运动帧创建了骨模型，并定性和定量地测量了它们 JSA 之间的明显差异。结果表明，在 RUD 和 FE 之间，腕骨关节内的 JSA 存在统计学上显著差异。这些研究为使用 4DCT 扫描测量腕部细微异常时开发方法学提供了第一步。
