Biomechanical study of screw fixation and plate fixation of a posterior malleolar fracture in a simulation of the normal gait cycle:

摘要

Category:AnkleIntroduction/Purpose:Fixation of the posterior malleolar fracture with plate or screws is under debating. A fatigue loading system and a spatial motion capture system will provide a theoretical basis for the selection.Methods:Thirty-six below-knee specimens with Haraguchi I type posterior malleolar fracture model was obtained. The specimens were randomly divided into two groups, Group A used two parallel-placed 3.5 mm semi-threaded hollow titanium alloy screws to fix the fracture from back to front; group B used an anatomical plate to fix the posterior malleolus. According to the ratio S of the area of the sagittal fracture over the total area of the distal tibial articular surface, each group was subdivided into three groups recorded as A1, B1; A2, B2; and A3, B3. In group A1 and B1, S=1/4; in A2 and B2, S=1/3; in A3 and B3, S=1/2. In the simulations of gait cycle, 4 kinds of ankle joints were subjected to mechanical loading. A fatigue loading system was used for repeated loading. The spati...