Locking compression plate (LCP) fixation is an established method of treatment of distal third tibial fractures. No biomechanical data exists in the literature regarding their use. Additionally no data exists on the biomechanical advantage of locking screw fixation over non-locking screw fixation for these fractures. In this study the axial and torsional stiffness, axial load to failure and fatigue performance of a 3.5 mm LCP medial distal tibia Synthes plate was evaluated for the stabilisation of distal third tibial fractures. Additionally the performance of the plate in uni and bicortical locked mode as well as non-locked mode was evaluated. A standardized oblique fracture pattern was created in the tibial metaphysis of 3rd generation composite tibias, 40 mm from the distal end of the tibia (AO 43-A2.3). A 10mm fracture gap was used to model a comminuted metaphyseal fracture. A 3.5 mm medial distal tibia LCP was applied with bi or unicortical locking or bicortical non-locking screws to 5 tibias respectively. All the bio-mechanical tests were performed on a Bose 3510 Electroforce material testing machine. A ramp to load, loading profile was used to determine the static axial and torsional performance of the construct. Fatigue testing simulated a 6 week gradual weight bearing régime with the load increasing every two weeks by 400N until either 250,000 cycles were completed or the construct failed.Introduction
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