Biomedical Engineering, University of Calgary, Calgary, Canada.
J Biomech. 2012 Aug 31;45(13):2215-21. doi: 10.1016/j.jbiomech.2012.06.004. Epub 2012 Jul 13.
Using a three-dimensional (3D) modality to image patients' knees before and after total knee arthroplasty (TKA) allows researchers and clinicians to evaluate causes of pain after TKA, differences in implant design, and changes in the articular geometry as a result of surgery. Computed tomography (CT) has not been fully utilized to date for evaluating the knee after TKA due to metal artifacts obscuring part of the image. We describe an accurate, validated protocol, which has been implemented in vivo, that improves visibility of the patellofemoral joint, matches implant models automatically in 3D, segments preoperative bone semi-automatically, detects and sets coordinate systems automatically, determines the six degrees of freedom of knee pose and geometry, and allows for multiple other measurements that are clinically relevant. Subjects are imaged at 0° and 30° knee flexion, while pushing on a custom-made knee rig to provide partial loadbearing. With some modifications, the protocol can be adopted by any group with access to a CT scanner and image analysis software, allowing for the investigation of numerous clinical and biomechanical questions.
使用三维（3D）模式对全膝关节置换术（TKA）前后患者的膝关节进行成像，可使研究人员和临床医生能够评估 TKA 后疼痛的原因、植入物设计的差异以及手术引起的关节几何形状的变化。由于金属伪影会使部分图像模糊，到目前为止，计算机断层扫描（CT）尚未被充分用于评估 TKA 后的膝关节。我们描述了一种准确的、经过验证的方案，该方案已在体内实施，它可以提高髌股关节的可视性，在 3D 中自动匹配植入物模型，半自动分割术前骨骼，自动检测和设置坐标系，确定膝关节姿势和几何形状的六个自由度，并允许进行其他多个与临床相关的测量。受检者在膝关节 0°和 30°弯曲时，同时按压定制的膝关节夹具以提供部分负重。通过一些修改，任何有 CT 扫描仪和图像分析软件的小组都可以采用该方案，从而可以研究许多临床和生物力学问题。
