Kirschner Wire Fixation in Dorsally Displaced Distal Radius Fractures: A Biomechanical Evaluation

Background  There is currently no consensus for the optimum configuration and number of Kirschner wires (K-wires) to use for the stabilization of dorsally displaced distal radius fractures. In this biomechanical study, we compared the load to failure and stiffness of four common K-wire configurations to identify the strongest construct for use in extra-articular dorsally displaced distal radius fractures. Case Description  We created a standard distal radius fracture model in turkey tarsometatarsi which was stabilized using two or three K-wires (1.6 mm) in four different configurations. Following a power calculation, 10 fracture models of each configuration underwent testing in cantilever bending and axial compression. Literature Review  Recent randomized trials have shown no evidence that volar locking plates are superior to K-wires for the treatment of dorsally displaced distal radius fractures. This has led to an increase in the popularity of much cheaper K-wires. Several different K-wire techniques have been described but there is no strong evidence to determine which is the optimal configuration and number of wires. Clinical Relevance  The three-wire interfragmentary configuration was stiffer than the three-wire Kapandji in axial compression and cantilever bending. There was no difference in load to failure in cantilever bending or axial compression. The three-wire interfragmentary technique is the stiffest configuration of K-wires for dorsally displaced distal radius fractures. The two-wire Kapandji technique was significantly weaker than the other configurations, especially in cantilever bending. Conclusion  The authors recommend to always use three wires for percutaneous pinning and never to use two intrafocal wires alone.