OBJECTIVE: To evaluate, both individually and comparatively, dynamic hip system-type plates marketed by two local manufacturers, to statistically analyze its results and show the lack of parameters for its manufacturing. METHODS: Static tests of flexion were carried out in five DHS plates of the manufacturer I (I group I) and in equal quantity of the same model of the manufacturer II (I group II), being all made in stainless austenitic ASTM F 138 steel, with four holes and a 135º angle. A servo-hydraulic MTS machine, Test Star II model, was used with a load capacity of 10 tons and dislocation control. The data were obtained from the applied load (P) as a function of the vertical dislocation of the piston (L), whose speed was 5mm/min. The tests were shutdown after reaching the maximum vertical flexion specified by the tests' standards. RESULTS: GroupI: flexion resistance, 161,4 ± 17,2 kgf rigidity, 64,5 ± 1,8 kgf/mm, flexibility, > 25,4 mm. Group II: flexion resistance, 124,7 ± 4,4,rigidity 59,6 ± 2,3, flexibility > 25,4 mm. For statistical analysis, the Mann-Whitney test was adopted and the determination of significance was 5 % (p <0,05). When the results obtained are compared, a significant difference can be noticed. CONCLUSION: The DHS plates of group I presented stronger flexion resistance (kgf) and stiffness (kgf/mm).
Hip fractures; Bone nails; Bone screws
