Improving the long-term performance of modular connections in artificial joints

自上世纪中叶以来，越来越多的人使用人工关节来治疗关节病变患者。早期主要治疗髋关节和膝关节，由于植入物的存活率通常低于15年，因此很少植入60岁以下的人。在过去的50年里，人工关节有了很大的进步，尽管越来越多的年轻人和更活跃的患者植入人工关节，但15年后，人工关节的存活率有望达到90%或更高。在过去的几年里，人工关节的改进包括制造分离的人造关节，如髋关节的头、颈和干，并在手术期间组装它们，包括初级手术和翻修手术。这些所谓的模块化设计允许外科医生在手术中对单个患者的大小、排列、关节类型和固定进行最佳调整。尽管在计算机建模和精细的近生理测试方面做了大量的工作，但这些较新的初级和修订设计似乎在其模块化连接上出现了问题。更常见的是，在髋关节的模块化头颈界面处，特别是在头部较大的髋关节，腐蚀会增加，从而导致组织反应，如囊肿、假瘤和肌肉损伤的形成。这项研究的长期目标是提高人工关节中模块化连接的性能，以减少由于断裂和腐蚀造成的修正。申请人和他的学生首先要研究的是头颈锥体的腐蚀和微动损伤。这种新试验将通过在回收的人工关节样本中再现临床“损伤”来验证。预期减少翻修手术将增加人工关节的成功长期性能，使患者受益，并降低医疗保健成本。马尼托巴大学和康科迪亚髋关节和膝关节研究所在这一专业领域对工程HQP进行培训，将支持加拿大医疗器械行业的发展。

Artificial joints have been used in increasing numbers since the middle of the last century to treat patients with diseased joints. Early on, mainly hip and knee joints were treated, and the devices were rarely implanted in persons younger than 60 years, as the implant survival rate was typically less than 15 years. Artificial joints have improved much in the last 50 years, and an implant survival rate of 90% or more can be expected after 15 years, in spite of the fact that they are increasingly being implanted in younger and more active patients. Improvements that were introduced in the last few years included manufacturing of artificial joints in separate pieces, such as the head, neck and stem in hip joints, and assembling them during surgery for both, primary and revision surgery. These so-called modular designs allow surgeons intra-operatively to optimally adjust the size, alignment, type of the articulation and fixation to an individual patient. Despite enormous efforts using computer modeling and elaborate near physiological testing, it appears that some of these newer primary and revision designs develop problems at their modular connections. More frequently, there is an increase in corrosion at the modular head-neck interface of hip joints, especially in hips with larger heads that can lead to tissue reactions such as the formation of cysts, pseudotumors and muscle damage. The long term goal of this research is to improve the performance of modular connections in artificial joints to achieve a reduction of revisions due to fractures and corrosion. The first study the applicant and his students will look at is the corrosion and fretting damage at head-neck tapers. The novel tests will be validated by reproducing clinical "damage" observed in a sample of retrieved artificial joints. The expected reduction of revision surgeries will increase the successful long-term performance of artificial joints benefitting the patients, and reduce the costs to health care. Training of engineering HQP in this area of expertise at the University of Manitoba and the Concordia Hip and Knee Institute will support the growth of the medical device industry in Canada.