Comparative finite element analysis of fixation strategies for sports-related tibial tuberosity avulsion fractures in adolescents: biomechanical evidence for optimized clinical decision-making.

Abstract

<h4>Objective</h4>This finite element study aimed to biomechanically compare screw fixation vs. K-wire fixation for adolescent tibial tubercle avulsion fractures (TTAF), investigating the differential biomechanical outcomes and physeal insult associated with each fixation method.<h4>Methods</h4>A finite element model of an adolescent tibia with a Modified Ogden type III fracture was developed. Three fixation types-(A) screws, (B) two non-crossing K-wires, and (C) four crossing K-wires-were tested both as standalone constructs and in their tension band-augmented counterparts. Simulations applied a 1,654 N tensile load to simulate patellar tendon force, with outcomes assessed by fragment displacement, bone and epiphyseal von Mises stress.<h4>Results</h4>Screw fixation (Type C3) demonstrated the highest stability, with fragment displacement of 1.97 mm and the lowest bone stress (295.79 MPa). K-wire constructs showed greater displacement and stress. The addition of a third fixator provided minimal stability improvement compared to two. Tension bands increased stability in K-wire models but raised bone stress to approximately 1,100 MPa and increased physeal stress.<h4>Conclusion</h4>Biomechanical analysis of TTAF reveals that screw fixation provides enhanced stability and reduced bone stress compared to K-wire fixation. Furthermore, the stability achieved with dual screws is comparable to that of triple screws, implying that adding more implants offers a limited advantage in fracture fixation stability. Considering the greatest physeal insult, particularly in skeletally immature individuals with retained growth potential, tension band wiring should be used sparingly. Based on these results, screw fixation is recommended as the optimal approach for adolescent TTAF.