Multi-Directional Mechanical Testing of Bone using CT-Compatible Loading Mechanisms

随着人口老龄化，关节炎正变得越来越普遍，加拿大关节炎联盟最近的报告表明，关节炎是加拿大人330亿美元的负担，其中包括医疗费用和生产力损失。在30年内，预计每4个加拿大人中就有一个会患上骨性关节炎。当患者的骨关节炎出现症状并与功能丧失相关时，患者可以通过关节置换手术的形式从手术干预中受益，在这种手术中，关节被植入物取代。典型的骨性关节炎，随着软骨的退化，关节会经历适应性变化。然而，治疗受到阻碍，因为人们对正常患者和骨关节炎患者之间的差异知之甚少，而且我们目前无法对患者特定的骨质量进行建模，使我们无法预测关节置换手术的成功。此外，外科医生目前无法考虑患者的骨骼质量来选择最优的植入物类型，使患者骨骼中的机械应力降至最低。较高的内部骨应力可能会导致微小的骨折，进而导致种植体松动并最终失败。这就需要进行翻修手术，这会增加患者的风险，并需要延长住院时间。翻修手术的费用也是原来关节置换手术的3到5倍，这进一步增加了我们医疗保健系统的成本负担。*本研究的目的是通过在高分辨率微型CT扫描仪中观察骨骼样本的内部结构的同时对骨骼样本施加实验力来开发和验证骨骼预测模型。骨的内部结构是复杂的，骨标本取自肩关节置换手术患者。在这项研究中，我们利用这些原本会被丢弃的患者骨骼碎片，并在实验室中对它们进行受力测试。对于需要关节置换的患者或有骨折风险的患者，对患者骨骼的力学测试对于提高我们对骨质量受损的了解至关重要。*虽然这项研究最初将在肩关节进行，但结果将转移到髋关节和膝盖等其他关节。最终，这项工作将为评估新开发的生物材料和可植入设备的机械性能提供新的方法，包括用于治疗骨关节炎的关节植入物。此外，这些新的针对骨骼患者的分析方法将导致新的诊断和预测工具的开发，外科医生可以使用这些工具来更好地了解个别患者的情况。这些进展有可能改善患者的手术结果。**

Arthritis is becoming more prevalent with the aging population, and recent reports from the Arthritis Alliance of Canada indicate that arthritis is a $33 Billion burden on Canadians, which includes healthcare expenses and lost productivity. Within 30 years, 1 in 4 Canadians is expected to have osteoarthritis. When a patient's osteoarthritis becomes symptomatic and associated with functional loss, then patients can benefit from surgical intervention in the form of a joint replacement surgery, in which the joint is replaced with implants. Typically with osteoarthritis, the joint undergoes adaptive changes as the cartilage degrades. However, treatment is hampered because differences between normal and osteoarthritic patients are poorly understood, and our current inability to model patient-specific bone quality prevents us from being able to predict the success of a joint replacement surgery. Also, surgeons are currently not able to consider the patient's bone quality to select an optimal implant type that minimizes mechanical stresses in the patient's bone. High internal bone stresses may lead to small fractures that progress to cause loosening of implants and eventual failure. This then necessitates a revision surgery, which places the patient at increased risk and requires prolonged hospital stay. Revision surgeries also cost 3 to 5 times more than the original joint replacement surgery, which further increases the cost burden on our healthcare system. ******The purpose of this research is to develop and validate bone predictive models by experimentally applying forces to bone samples while viewing their internal structure in a high resolution micro-CT scanner. The internal structure of bone is a complex Bone samples are acquired from patients who undergo shoulder replacement surgery. In this research, we utilize these patient bone fragments that would otherwise be discarded, and we test them with applied forces in the laboratory. Mechanical testing of patient bone is essential to improve our understanding of compromised bone quality in patients requiring joint replacements, or who are at risk of fracture. ******While this research will initially be conducted in shoulder bone, the resulting work will be transferrable to other joints like hips and knees. Ultimately, this work will provide new methods to assess mechanical performance of newly developed biomaterials and implantable devices, including joint implants used in the treatment of osteoarthritis. Additionally, these new bone patient-specific analysis methods will lead to the development of new diagnostic and predictive tools that surgeons can use to better understand the case of the individual patient. These advancements have to potential to improve surgical outcomes for patients.**