| Fracture is the combined effect of internal and external factors, in addition to age, gender, health status and other systemic factors, internal skeleton refers to the bone characteristics such as material properties and structural characteristics; external skeleton means suffered size and direction of external forces, and relative position of the limb. In the clinical treatment of fractures, only by fully understanding the mechanism of fracture formation process, possible trends and consequences, we can provide a basis for classification, grab the clinical treatment characteristics, and thus decide treatment options, prognosis, and further improve the efficacy. Distal radius fracture is a common injury in sports system which has been paying attention in clinical. Qualitative research in the past on the analysis of distal radius fracture mechanism emphasis on theoretical derivation. Biomechanical analysis has been mostly concentrated in the corpse experiments and two-dimensional finite element analysis(FEA). Research of distal radial fractures mechanisms using three-dimensional FEA has not found yet.FEA is carried out by means of computer numerical computation method, the continuity of the entity to be analyzed into limited discrete units, each unit in combination to replace the original continuum, and one by one study of mechanical properties of each unit. Compared with traditional biomechanical experiments, the advantage of FEA is reflected in low cost, short cycle calculation, high simulation accuracy, repeatability without loss, to calculate the internal stress and strain, results can be visualized analysis, simulation experiments can be study of the physiological condition. The need for research scholars such as transverse carpal ligament resection influence on the stability of the wrist, the scaphoid fracture after changing the mechanical properties of the wrist, and the evaluation of the merits of miniature external fixator Bennett Kirschner treatment of fractures, have been established different three-dimensional finite element model of the wrist.In this study, wrist CT images of a young male volunteer were processed by image processing and the use of3D FEA pre-processing software. A3D FEA model including the full-length radius and ulna, wrist joint surface cartilage, tendon forearm interosseous membrane part radio-scapholunate ligament, radial head boat ligament, radial ligament, radio-scapholunate ligament, ulnar ligament, foot triangular ligament, the ulnar capsule structure volar radioulnar ligament, dorsal ulnar ligament, radial triangular ligament, triangle radioulnar ligaments and wrist fibrocartilage disk was established with integrity structure and accurate anatomical location. Comparing the results with previous studies demonstrates the effectiveness of the model. The model contributes to further clarify the biomechanical characteristics of the various structures of the wrist at different mechanical effects under load conditions, the relevant mechanical wrist fracture mechanism analysis, improvement and other fixation methods with the reference value.Through the rotation and translation operations neutral position of the wrist above the3D FE model established, simulation constructed bit wrist dorsiflexion15°,30°position,45°position,60°position,75°position,90°position. By applying a fixed axial load100N dorsiflexion angle for different models, the radio-carpal joint surface Von Mises Stress clouds were obtained. By observing cloud, it is found that as wrist dorsiflexion angle increases, the stress distribution shifted focus to the dorsal region of the articular surface of the more dorsal articular surface load transfer radio-carpal articular surface accounted for the greater percentage of the entire amount of load transfer, and dorsiflexion the angle reaches45°, the angle increases with the increasing trend decreased.In summary, the present study established the structural integrity, the exact anatomical location of the3D FE model of the wrist, by comparing with the results already demonstrate the effectiveness of the model; and on this basis to build different analog wrist dorsiflexion3D FE model of the angle, at a fixed axial load, through the analysis of the impact of different dorsiflexion angle articular surface stress distribution for3D modeling and biomechanical studies of individual wrist provides a technology platform and reference methods and distal radius fracture mechanisms were discussed. |
