The shape memory alloys exhibit a number of remarkable properties, which open new possibilities in engineering and more specifically in biomedical engineering. The most important alloy used in biomedical applications is NiTi. This alloy combines the characteristics of the shape memory effect and superelasticity with excellent corrosion resistance, wear characteristics, mechanical properties and a good biocompatibility. These properties make it an ideal biological engineering material, especially in orthopaedic surgery. In this work, modular plates for the osteosynthesis of the long bones fractures are presented. The proposed modular plates are realized from modules, completely interchangeable, made from Titanium or Stainless steel materials, having as connecting elements U-shaped staples made of Nitinol. Using computed tomography (CT) images to provide three-dimensional geometric details, and SolidWorks CAD software, the virtual models for humerus bone and for modular platesare generated. For numerical simulation we used VisualNastran software. We have obtained the displacements diagram, the von Mises strain diagram and von Mises stress diagram. Using the Rapid Prototyping 3D Zcorp 310 Printer system, we have obtained the prototype for the human humerus bone and for the plate modules. In vitro experiments are realised on the cadaver bones using metallic modular plates. The advantages of the modular plates are presented.