Three-dimensional finite element analysis on intramedullary controlled dynamic nailing for femoral shaft fracture / 中国组织工程研究

ABSTRACT

BACKGROUND:Interlocking intramedul ary nail complications contain nail bent or broken, exit, re-fracture at spiketail or nail hole. Thus, our team designs a novel intramedul ary control ed dynamic nail. OBJECTIVE:To evaluate the rationality and safety of intramedul ary control ed dynamic nail design and strength, and to give rational proposal for its clinical application. METHODThe three-dimensional finite element models of composite femur, transverse fractures of the femoral shaft were constructed with intramedul ary control ed dynamic nailing. The stress and strain were detected under vertical loads and gait cycle. RESULTS AND CONCLUSION:The maximum stress of the intact femur under the compression load was at femoral neck and the medial and lateral aspects of the femoral shaft;while the stresses of fractured femur were at the interface between screw and screw hole. In gait cycle, in case of intact bone, large stresses were found in the distal 1/2 of anteriomedialis of femoral shaft;while the stress distribution in fractured femur was similar with the  former. Intramedul ary control ed dynamic nailing has the ability of generating compression between fragments. These suggest that intramedul ary control ed dynamic nailing is rational and good at design and biomechanical properties.