Biomechanical analysis of different osteosynthesis configurations in the pin and plate fixation method for distal humerus fractures

Abstract

Distal humerus fractures commonly occur in adults with low bone mineral density causing major technical challenges for orthopedic surgeons. Persian fixation method was introduced as a novel technique to stabilize small fragments in comminuted distal humerus fractures using a set of K-wires and a reconstruction plate. The present study aims to measure this technique's stiffness and stability of this technique and analyze the effect of influential parameters with numerical simulation and biomechanical testing on a cadaveric specimen. Validation of the finite element (FE) model was conducted based on results of experiments. The results indicated that Delta configuration mainly led to a higher stiffness in the case of axial loading and anterior bending compared to L configuration. Analyzing the influential factors of this technique suggests that changes in diameter and number of K-wires have a similarly significant effect on the construct stiffness while the height of plate had a slight influence. Also, the diameter of wires was the most effective parameter for implant failure, particularly in the 3-pin construct, which caused a reduction in failure risk by about 60%. The results revealed that the Persian fixation method would achieve suitable stability compared to the dual-plating technique.

Cadaveric biomechanical assessment of different configurations for a novel pin and plate fixation method in distal humerus fractures

“…In the present study, out of the three investigated pin configurations, groups I and III were included with the aim to ascertain the results of our previous FE study regarding the effect of K-wire diameter in the overall fixation structure stiffness 22 . Group II was added to explore a new factor (i.e., K-wire arrangement) and whether this factor can affect the structure stiffness.…”

“…Also, two finite element (FE) studies have been carried out regarding the Persian fixation technique which investigated the biomechanical behavior of the Persian fixation technique under various loading conditions. Hakiminejad et al 22 modeled different configurations of K-wire number, diameter, and plate position to analyze their effects on fixation stiffness. Another FE study by Jitprapaikulsarn and others found their tested variation of the method to have overall comparable stability to the conventional methods except in internal rotation loading 23 .…”