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There were no significant differences between the two techniques, since the observed stresses are well below the flow stress of the material, ensuring good safety factor (ranging from 3.5 to 4.1).

High-strength steels such as DOMEX 700 combine high mechanical strength and great ductility. However, when processed by welding their microstructure could present grain growth and deleterious phase formation. Nevertheless, using highpower GMAW-P the effects of electrode and shielding gas composition on the mechanical and microstructure properties of DOMEX 700 welded joints need to be understood. Thus, wire electrodes such as AWS ER 90S-D2 (A1) and AWS ER 120S-G (A2), and shielding gases such as Ar ? 15% CO 2 (G1) and Ar ? 8% CO 2 (G2) were used and the microstructure of welded joints was analyzed through optical and scanning electron microscope (SEM). Mechanical properties of joints was characterized through joint tensile test, impact test from 20 to-40°C, and microhardness in the joint cross-sectional. It is possible to highlight the increase in strength and elongation values with the use of electrode A2, and reduction in impact energy values for specimens welded by gas mixture G2.

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Objective: This research presents a biomechanical analysis performed in the lumbar spine of a porcine animal model, considering a minimally invasive technique for the treatment of split fractures. Methods: Porcine spines were used to perform compression tests, considering three different approaches. Three groups were defined in order to verify and validate the proposed technique: a control group (1); spines with split fractures (2); and a treatment group (3). For the first group (control), spines were axially compressed until any kind of fracture occurred, in order to verify the strength of the structure. In the second group, split fractures were created to obtain the mechanical failure pattern of the model. In the third group, the split fractures were submitted to the proposed treatment, to verify the resistance achieved. The three groups were compared by means of axial compression tests. Statistical analysis was performed by ANOVA. Results: The control group (intact spine) and the treated split fracture group presented similar results (p>0.05), differing from the results for the untreated split fracture group (p<0.05). Conclusions: The tests performed in order to determine the behavior and strength of the lumbar spine when subjected to axial compression provided positive data for the development of a minimally invasive technique capable of restoring split fractures of the spine. Level of evidence III; Experimental research.