Biomechanical Evaluation Method to Optimize External Fixator Configuration in Long Bone Fractures—Conceptual Model and Experimental Validation Using Pilot Study

Abstract

External fixation is a commonly used method in stabilizing fracture sites. The performance of the fixator depends on how it affects the mechanical properties of the fracture site and is governed by parameters like the fixator type and fixator configuration. Identifying ideal configurations prior to surgery will help surgeons in planning the procedure, limiting the possibility of complications such as non-union. In this study, a framework has been proposed as a surgical pre-planning tool, to assist surgeons compare mechanical properties of a fracture site under different fixator configurations, and thereby identify the optimum solution. A computational tool was identified as the best method for this purpose. Cost and time of computation were given special consideration to reduce complexity in clinical settings. A pilot study was conducted on a section of the proposed framework, where the aim was to understand the feasibility of implementation. In the pilot study, a unilateral uni-planar fixator on a simple diaphyseal transverse fracture was analyzed. During the pilot study the selected fixator was tested and a few models were developed to assess system stability. The models were then compared to identify the optimum model that could be used with the proposed framework. The proposed framework provided a suitable solution for the use case and out of the models developed the simplified finite element model was identified as the best option for the use case.

Keywords

• biomechanics
• stability
• fracture healing
• external fixation
• long bone fractures
• mechanical testing