BIOMECHANICAL EVALUATION OF TENSION BAND PLACEMENT FOR THE REPAIR OF OLECRANON FRACTURES

Displaced transverse fractures of the olecranon commonly are treated b y open reduction and internal fixation using the AO tension band wirin g technique, Reports that the AO technique has a tendency to open the fracture site at the articular surface prompted Rowland and Burkhart t o modify placement of the tension band, The present study tested the h ypothesis that the modified wire placement provides static compression anteriorly, and hence better reduction at the articular surface of th e fracture, than the AO technique under static conditions, Transverse olecranon fractures were created on 8 pairs of fresh cadaveric arms, O ne ulna of each pair was repaired using the modified wire placement, w hereas the contralateral ulna was repaired using the AO technique, The humerus was driven into the trochlear fossa of each ulna using a serv ohydraulic testing machine while a force transducer and video system m easured the applied force and gap formation at the articular surface o f the fracture, Because the static behavior of the fixations was teste d, no muscle forces were included, Results indicated no significant di fferences in yield loads or stiffness values between the 2 techniques, Based on the results of this static study, the modified wire placemen t does not provide increased stability of fracture fixation compared w ith the AO tension band wiring technique.