Medical imaging of knee kinematics after joint replacement

人们接受膝关节置换术的主要原因是为了减轻关节炎引起的疼痛。 不幸的是，有些人在手术后仍然有相当大的疼痛，通常在膝盖骨区域（称为膝前疼痛）。这种疼痛通常是由于部件设计不当、部件放置不当、软组织过紧或手术技术不佳导致膝盖骨（髌骨）在大腿骨（股骨）上的轨迹不正确。目前，大多数外科医生用来“查看”膝盖内部的唯一方法是X射线，这是膝关节屈曲单一角度的二维图像。这些提供的信息不足以研究骨骼的运动。 我们建议开发一种新的方法来测量膝关节置换手术后，在不同的屈曲角度，使用计算机断层扫描（CT）的骨骼和组件的三维位置。 CT产生患者膝盖的3D图像。金属部件在图像上产生条纹，使得难以准确识别骨骼和部件，但是我们提出了几种方法来解决这个问题。我们将使用插入尸体膝关节样本的参考阵列来确认方案。然后，我们将该方案应用于患者，以判断最近的植入物设计是否改善了髌骨运动;随后，我们将比较有疼痛和无疼痛的患者。此外，与CT相比，我们将开发一种用于二维荧光透视成像的协议，其是动态的（即捕获运动视频），廉价的，广泛可用的，并且可以应用于

The primary reason for someone to get a knee replacement is to reduce his or her pain due to arthritis. Unfortunately, some people still have considerable pain after the surgery, often in the region of the kneecap (called anterior knee pain). Frequently this pain is attributed to incorrect tracking of the kneecap (patella) on the thigh bone (femur) due to improper component design, incorrect placement of the components, excessively tight soft tissues or poor surgical technique. Currently, the only method most surgeons use to 'look inside' the knee is X-rays, which are two-dimensional images at a single angle of knee flexion. These provide inadequate information to study the movements of the bones. We are proposing to develop a new method to measure the three-dimensional positions of both the bones and components after knee replacement surgery at different flexion angles, using computed tomography (CT). CT produces a 3D image of the patient's knees. The metal components create streaks on the image, making it difficult to identify the bones and components accurately, however we are proposing several ways to address this. We will validate the protocol using reference arrays inserted into cadaveric knee specimens. We will then apply the protocol to patients in order to judge whether or not a recent implant design improves kneecap motion; subsequently, we will compare patients with and without pain. In addition, and in contrast, to CT, we will develop a protocol for two-dimensional fluoroscopic imaging, which is dynamic (i.e. captures a video of movement), inexpensive, widely available and could be applied in