Biomechanical Analysis of a Novel Syndesmotic Plate Compared With Traditional Screw and Suture Button Fixation

Abstract

Many lateral malleolus fractures have been found to have syndesmosis injuries after anatomic reduction. The main methods for the treatment of syndesmosis injuries are screw fixation and suture-button flexible fixations. In pursuit of innovation, we have designed a novel syndesmotic plate (NSP) for simultaneous fixation of lateral malleolus fractures and distal tibiofibular syndesmosis injuries. The purpose of this study is to compare the biomechanical characteristics of the NSP to syndesmotic screw and suture-button fixations. Twelve adult cadaveric specimens were used in this experiment. Axial loading as well as rotation torque were applied in 3 different ankle positions: neutral, dorsiflexion, and plantarflexion. After the initial specimens were tested, they were made into a pronation-abduction III fracture model as described by Lauge-Hansen. Subsequently, the specimens were fixed sequentially using a distal fibular anatomic locking plate (DFALP) combined with syndesmotic screws, DFALP combined with suture button, and NSP. Then the above tests were repeated. The syndesmotic displacement and the strain of the tibia and fibula were recorded during the experiment. In most cases, the displacements and strains of the NSP group and the screw group were smaller than the suture button groups and the native (SBGAN) (p < .05), and the displacements and strains of the NSP group were also slightly smaller than the screw group in most cases, and there was no significant difference between the 2 groups. The NSP we developed has a fixed strength no less than the traditional syndesmotic screw fixation. This provides us a new idea for the treatment of distal tibiofibular syndesmosis injuries.