CANNULATED SCREW FIXATION VERSUS TENSION BAND WIRING OF FRACTURES OF THE TUBEROSITY OF THE CALCANEUM.

Abstract

INTRODUCTION – Tuberosity fractures of the calcaneum are rare injuries. The traditional operative treatment involves open reduction and internal fixation with a tension band wire construct. We have developed a new technique of fixing these fractures with internal fixation using cannulated screws and a figure of eight wire. This paper describes the new technique outlining its advantages and compares the 2 methods of fixation biomechanically to determine their properties with respect to fracture fixation.

METHOD – 20 sections of bovine bone were taken to act as an experimental model for the calcaneum. They were osteotomised to create the posterior process fracture model. 10 were fixed using a traditional tension band wire construct and 10 were fixed using the cannulated screw and wire construct. Each construct was subjected to biomechanical testing to identify the stiffness, energy to failure and load to failure.

RESULTS – During loading the cannulated screw and wire constructs showed a significant increase in stiffness and energy to failure compared to the tension band wire constructs

CONCLUSION – The increased stability of the cannulated screw construct demonstrated by the testing offers biomechanical benefit over the traditional tension band wire construct. This, as well as the improved technical aspects of the cannulated screw fixation, may be beneficial for clinical use.