Optimum Screw Configuration for the Fixation of Sanders Type IIC Tongue-Type Fractures? A Biomechanical Study.

Abstract

The minimally invasive technique (percutaneous screw fixation) is one of the options for treating tongue-type IIC fractures successfully. The aim of this study was to assess the biomechanics of four different screw configurations used for the fixation of tongue-type IIC calcaneal fractures. Identical osteotomies, recapitulating a type IIC injury, were created in synthetic calcaneus specimens using a saw. The specimens were randomly assigned to one of the four fixation groups (n = 7 per group): two divergent screws, two parallel screws, two parallel screws plus one screw axially oriented toward the sustentaculum tali, and three parallel screws. A load test was performed on all of the groups, and the specimens were then tested using offset axial loading until 2, 4, and 5 mm of fracture displacement occurred. Mean force values for the three-parallel screw construct at 2-, 4-, and 5-mm fracture displacements were found to be significantly higher compared with those for the other groups. The use of a three-parallel screw construct seems to provide more stability in the treatment of tongue-type IIC fractures.