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

Abstract

Elbow dislocation and instability present significant clinical challenges, necessitating a thorough understanding of the underlyingbio-mechanical mechanisms. In this study, a quasi-static three-dimensional finite element model of the human elbow joint isdeveloped to investigate stress distribution and stages of dislocation in the human elbow under various loading conditions. Themodel simulates the elbow joint in different degrees of flexion (30°, 45°, 60°, and 90°) and forearm positions (pronation andsupination), providing detailed insights into the progression of dislocation. Significant findings include the identification of highstress concentrations on the humerus at 90° flexion and on the radial and coronoid processes at 30°, 45°, and 60° flexion.Three reproducible stages of dislocation were observed, particularly in flexed positions with forearm pronation or supination.These stages align with experimental observations1 and highlight the initial occurrence of bony failures, such as radial headand ulnar coronoid fractures, preceding soft tissue tears. Clinically, the study underscores that early-stage low-impact posteriorelbow dislocations retain enough stability to be managed with closed reduction and early mobilization. However, as dislocationsprogress, significant damage to the medial and lateral collateral ligaments is expected, necessitating more invasive treatments.This research provides valuable bio-mechanical insights into elbow dislocation, aiding in the development of improved treatmentstrategies and enhancing patient outcomes through precise and timely clinical interventions. The validated FEM serves as apowerful tool for pre-surgical planning offering a comprehensive understanding of elbow joint mechanics