Abstract: BACKGROUND: There are few studies on dynamic biomechanical analysis of Kirschner wire tension band steel wire in different winding methods for the treatment of transverse patella fractures.  
OBJECTIVE: To analyze the biomechanical difference between the “8”-shaped Kirschner wire tension band fixation and the “0”-shaped Kirschner wire tension band for the treatment of transverse patella fractures in the complete gait cycle using three-dimensional reconstruction technology.
METHODS:  Based on the CT scan data of the human knee joint, Mimics, Geomagic Studio, Hypermesh and Abaqus and other three-dimensional reconstruction softwares were used to establish the “8” and “0” shape Kirschner wire tension band to treat the finite element model of the patella transverse fracture. A complete gait cycle of the knee joint after surgery was simulated by loading the material properties, setting boundary conditions, applying loads and other operations. The difference in displacement and stress between the two fixed models was analyzed.  
RESULTS AND CONCLUSION: (1) In the complete gait cycle, the change of stress value was positively correlated with the change of buckling angle, and the maximum stress reached at 70% of the gait cycle. In the same gait instant, the stress of each component of the “0” model was less than that of the “8” model. (2) The displacement value of each component of the two models increased with the increase of the flexion angle during a complete cycle, and reached the peak displacement at 70% of the gait cycle. In the same gait instantaneously, the “0”-shaped model was different. The displacement values of the components were all smaller than those in the “8” model. At the peak of the displacement, the displacement values of the patella, Kirschner wire and steel wire of the “0” model were 10%, 11%, and 13% smaller than those of the “8” model. (3) The results show that during the complete gait cycle, the high stress areas of the two tension band models are mainly concentrated near the patella fracture line and the contact part of the internal fixation, but the stress peak value of each component in the “0” model is less than “8”-shaped model, and it is better than the “8”-shaped tension band model in terms of the stability of the fracture end and internal fixation, and has a better biomechanical effect.

Key words: patella, transverse fracture, tension band, biomechanics, gait cycle, Kirschner wire, finite element