Biomechanical evaluation of tension band placement for the repair of olecranon fractures.

Abstract

Displaced transverse fractures of the olecranon commonly are treated by open reduction and internal fixation using the AO tension band wiring technique. Reports that the AO technique has a tendency to open the fracture site at the articular surface prompted Rowland and Burkhart to modify placement of the tension band. The present study tested the hypothesis that the modified wire placement provides static compression anteriorly, and hence better reduction at the articular surface of the fracture, than the AO technique under static conditions. Transverse olecranon fractures were created on 8 pairs of fresh cadaveric arms. One ulna of each pair was repaired using the modified wire placement, whereas the contralateral ulna was repaired using the AO technique. The humerus was driven into the trochlear fossa of each ulna using a servohydraulic testing machine while a force transducer and video system measured the applied force and gap formation at the articular surface of the fracture. Because the static behavior of the fixations was tested, no muscle forces were included. Results indicated no significant differences in yield loads or stiffness values between the 2 techniques. Based on the results of this static study, the modified wire placement does not provide increased stability of fracture fixation compared with the AO tension band wiring technique.