New Techniques of Olecranon Tension Band Fixation: Biomechanical Evaluation Using Finite Element Method

Abstract

Various fixation methods have been used to fix olecranon fractures including the plate fixation, intramedullary screws, and tension band technique. Open reduction with tension band wire fixation (TBW) has been widely accepted for the treatment of transverse displaced olecranon fractures. The aim of this study was to determine the stress developed in different types of TBW fixations in olecranon fractures on the basis of finite element analysis. A 3-dimension model of the elbow joint was created on the basis of the computerized tomography scan images. Three different configurations of TBW fixations were evaluated in this study. The stress developed in various fragments and implant parts and relative motion of implant in various degrees of elbow flexion was assessed in this study. The stress of K-wires was higher in condition 1 (K-wire inserted from the posterior side to the posterior side) compared with other conditions. The relative displacement of the pin was the highest in condition 2 (K-wire from posterior to anterior) (higher than 2 mm), which occurred in elbow flexion angle of 40 to 50, followed by condition 3 (with K-wire, one from posterior to anterior and another one from posterior to posterior). It seems that the lowest value of displacement occurs in condition 1, compared with other conditions. The new methods suggested herein (conditions 2 and 3) provided sufficient stability for fracture fixation, similar to the conventional method (condition 1). In these 2 methods, the amount of complications seems to be lower because of the placement of K-wires, therefore, these 2 methods are recommended to reduce the complications of surgery.