Resumo

SARDENBERG, Trajano; MULLER, Sérgio Swain; MEDEIROS, Daniel Ricardo  e  BAPTISTAO, Pablo Luiz. Mechanical study on dorsal stability of intramedullary osteosynthesis associated with external fixation (Ulson's method). Rev. bras. ortop. [online]. 2011, vol.46, n.6, pp. 656-659. ISSN 0102-3616.  http://dx.doi.org/10.1590/S0102-36162011000600006.

OBJECTIVE: To evaluate the Ulson intramedullary fixation method, with external fixation in which the level of the external locking of the Kirschner wires is varied, and without external fixation. METHODS: Eighteen porcine tibias were used. Transverse osteotomy was performed in the region of the tuberosity, and two intramedullary Kirschner wires were inserted into each specimen, using three different assembly patterns: Group I: locking with external minifixator at a height of 3.0 cm; Group II: locking at a height of 4.5 cm; Group III: without external locking. Mechanical shear tests were then conducted, to determine the maximum load, proportionality limit and coefficient of rigidity. RESULTS: There were no significant differences in maximum load or proportionality limit between the groups. The coefficient of rigidity was higher in Group II. CONCLUSION: The locking height for the Kirschner wires in Ulson's method, within the limits evaluated, did not harm the stability of the fracture fixation system.

Palavras-chave : Radius Fractures; External Fixators; Biomechanics.