Analysis Developed from an Extremely Complex System of the Human Shoulder Based on Finite Element Method (FEM)

With the application of different computational tools, it has been possible to develop virtually reliable 3D models of anatomical structures. So, it is possible to determine the physical state of patients with deleterious conditions, granting diagnoses the advantage of not compromising the physical integrity of the patient and performing adequate rehabilitation. In the first instance, it can be applied for biomechanical evaluation through numerical simulation to determine the capacity of a system or structure to support loads and stresses under different situations. This work is to develop a highly complex numerical bio-model of the human shoulder articulation. The complex bio-model considers bone tissue (trabecular bone and cortical bone), cartilage, and ligaments. The bio-model is implemented utilizing magnetic resonance imaging and evolves to be functional in a finite element method computational package. The shoulder joint is highly complex because the range of motion is greater than the ranges of motion of other joints in the human body. In addition, it is unstable since the shoulder is attached to the upper trunk of the body by static stabilizers (ligaments) and dynamic stabilizers (muscles). This makes it prone to suffer different types of injuries, such as dislocations and tears, which are classified depending on the area. An extremely complex bio-model was developed that allows the morphological behavior of the upper extremity with characteristics similar to biological tissue and to be able to carry out a study that defines a structural mechanical behavior. The main point of this research is to develop a three-dimensional model of the shoulder of a healthy adult from a magnetic resonance scan, confirmed by the three joints; sternoclavicular, acromioclavicular, and glenohumeral and their cortical, trabecular bone components, taking into consideration articular cartilage and ligaments. A numerical evaluation of the flexion movement is completed by adding each of the mechanical properties of the biological tissue used. Likewise, boundary conditions are established in the scapula and clavicle (restricting movement in a specific area) to apply an external force that generates movement and determines effects directed at shoulder instability or the area prone to suffering a tear. With this work, the bases are established to propose preventive physiotherapeutic treatments before reaching the surgical intervention. In addition, through these models, post-operative recovery treatments can be developed.