Is the novel olecranon tension plate a valid alternative to tension band wiring of olecranon fractures? A biomechanical study on cadaver bones.

Abstract

Tension band wiring (TBW) used for olecranon fractures is afflicted with a high rate of complications. The aim of this study was to compare the stability of the TBW versus an alternative, novel low-profile olecranon tension plate (OTP) with angular stable screws in a simulated complex fracture model. Nine fresh-frozen pairs of cadaver proximal ulnae with an oblique osteotomy and an additional wedge fragment simulating an unstable fracture were tested. The TBW and OTP were implanted pairwise. The elbow motion was simulated in a single-muscle model and ranged from full extension to 90° of flexion. The pulling force of the triceps tendon ranged from 50 to 200N. The displacement of the fracture fragments was measured with a video motion analysis system over 304 cycles. Data were assessed statistically using the Wilcoxon signed-rank test. The cyclic loading tests showed mean loosening of the fracture fragments at the articular surface of 0.56mm using TBW (SD 0.65) and 0.15mm for OTP (SD 0.39). There was no statistical significance in loosening between the two constructs (p=0.31). No plate breakage or screw loosening occurred. The low-profile OTP, using the principles of pre-tensioning, lag, cortical, and angular stable screws together, demonstrated similar stability after olecranon fracture fixation when compared with the TBW technique and a lag screw in the olecranon fracture model with a third wedge fragment.