Syndesmotic fixation has been extensively investigated. Screw size, number, position, orientation, and flexible fixation options have all been investigated at length. There is however a lack of knowledge of any difference between an independent syndesmotic screw versus onethrough a lateral plate. The purpose therefore is to perform a biomechanical assessment of syndesmotic fixation comparing independent screw vs screw through plate combination, analyzing torsional strength of both constructs. To perform this, seven matched cadaveric through tibia-fibula lower leg specimens were prepared by creating an oblique fracture performing surgical syndesmotic disruption. The specimens were then randomized into the direct lateral through plate group (DL) and the other to the posterolateral independent screwgroup (PL). The fractures were treated with either (1) lateral plate with syndesmotic fixation through the plate, (2) posterolateral antiglide plate with an independent syndesmotic screw. The specimens were then secured into a loading frame and stressed with axial and external rotation forces to 6.5 nm and then to failure. An a-priori power analysis using in-lab cadaveric data and relevant literature was completed using TTF analyses. Results demonstrate a potential biomechanical advantage to inclusion of a syndesmotic screw through a laterally based implant, when compared to an independent screw orthogonal to fibular fixation. Results show decreased displacement at the syndesmosis when an external rotation stress is applied, however, overall construct stiffness trended towards superiority in the direct lateral group, the difference did not reach statistical significance.
Keywords
Syndesmotic fixation, cadaver, biomechanics
Abstract
Article
