Department of Mechanical Engineering, École de technologie supérieure, 1100 Notre-Dame West, Montreal, Quebec H3C1K3, Canada.
Faculty of Veterinary Medicine, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Quebec J2S2M2, Canada.
Med Eng Phys. 2019 Sep;71:17-29. doi: 10.1016/j.medengphy.2019.07.005. Epub 2019 Jul 18.
Osteosarcoma is the most common type of bone cancer in dogs, treatable by amputation or limb-sparing surgery. For the latter, commercially available plate - endoprosthesis assemblies require contouring, to be adapted to the patient's bone geometry, and lead to sub-optimal results. The use of additively-manufactured personalized endoprostheses and cutting guides for distal radius limb-sparing surgery in dogs presents a promising alternative. Specialized software is used for the bone structure reconstruction from the patient's CT scans and for the design of endoprostheses and cutting guides. The prostheses are manufactured from a titanium alloy using a laser powder bed fusion system, while the cutting guides are manufactured from an ABS plastic using a fused deposition modeling system. A finite element model of an instrumented limb was developed and validated using experimental testing of a cadaveric limb implanted with a personalized endoprosthesis. Personalized endoprostheses and cutting guides can reduce limb sparing surgery time by 25-50% and may reduce the risk of implant failure. The numerical model was validated using the kinematics and force-displacement diagrams of the implant-limb construct. The model indicated that a modulus of elasticity of an implant material ranging from 25 to 50 GPa would improve the stress distribution within the implant. The results of the current study will allow optimization of the design of the personal implants in both veterinary and human patients.
骨肉瘤是犬类最常见的骨癌类型，可通过截肢或保肢手术治疗。对于后者，市售的钢板-内置假体组件需要进行塑形，以适应患者的骨骼几何形状，但这会导致结果不理想。在犬类桡骨远端保肢手术中使用增材制造的个性化内置假体和切割引导器是一种很有前途的替代方法。从患者的 CT 扫描中使用专门的软件进行骨骼结构重建，并设计内置假体和切割引导器。假体由钛合金制成，使用激光粉末床熔合系统，而切割引导器由 ABS 塑料制成，使用熔丝制造系统。开发了一个带有仪器的肢体的有限元模型，并通过对植入个性化内置假体的尸体肢体进行实验测试进行了验证。个性化内置假体和切割引导器可将保肢手术时间缩短 25-50%，并可能降低植入物失败的风险。该数值模型通过植入物-肢体结构的运动学和力-位移图进行了验证。该模型表明，弹性模量在 25 到 50 GPa 范围内的植入物材料可改善植入物内的应力分布。本研究的结果将允许在兽医和人类患者中优化个性化植入物的设计。
