Investigating Elbow Dislocation and Instability: A 3D Finite Element Analysis Approach

Elbow dislocation and instability present notable clinical challenges, requiring a comprehensive understanding of the underlying biomechanical factors. This study develops a quasi-static three-dimensional finite element model (FEM) of the human elbow joint to examine stress distribution and the progression of dislocation under different loading conditions. The model evaluates the joint at varying flexion angles (30°, 45°, 60°, and 90°) and forearm orientations (pronation and supination) to provide a detailed analysis of dislocation dynamics. Key results indicate significant stress concentrations on the humerus at 90° flexion, while the radial and coronoid processes experience high stress at 30°, 45°, and 60° flexion. The study identifies three consistent stages of dislocation, particularly in flexed positions with forearm pronation or supination. These findings align with experimental data [1], revealing that bony fractures, such as radial head and ulnar coronoid failures, commonly precede soft tissue damage. Clinically, the research highlights that early-stage posterior elbow dislocations, when caused by low-impact forces, retain sufficient joint stability for non-invasive management through closed reduction and early mobilization. However, as dislocations progress, extensive damage to the medial and lateral collateral ligaments becomes more likely, often requiring surgical intervention. This study provides valuable biomechanical insights into elbow dislocation, contributing to the refinement of treatment approaches and improved patient outcomes. The validated FEM serves as an effective tool for pre-surgical assessment, enhancing the understanding of elbow joint mechanics and guiding clinical decision-making.