Biomechanical properties of retrograde interlocking intramedullary nail versus less invasive stabilization system plate in the repair of distal femoral fractures / 中国组织工程研究

ABSTRACT

BACKGROUND:Distal femoral fractures are mainly treated with less invasive stabilization system (LISS) plate or retrograde interlocking intramedul ary nail fixation, but choosing which method is controversial, and studies on their biomechanical properties are few. OBJECTIVE:To compare the biomechanical stability of retrograde interlocking intramedul ary nail and LISS plate fixation in the treatment of distal femoral fractures. METHODS:Twelve male cadaveric femurs were col ected, and the injured, with abnormal bone density and osteonosus specimens were excluded through X-ray examination, fol owed by randomly divided into two groups. Models of AO type A3 supracondylar fracture were prepared, and were fixed with LISS plate and retrograde interlocking intramedul ary nail, respectively. The compressive stiffness and displacement values under axial compression and loading of 100, 300 and 500 N, as wel as the bending strength of the specimens under bending load were observed. RESULTS AND CONCLUSION:(1) The resistance to axial deformation capacity (compressive stiffness) of the LISS plate was superior to the retrograde interlocking intramedul ary nail (P0.05). (2) Under axial compressive loading of 100, 300 and 500 N, the displacement values of LISS plate were significantly less than those of the retrograde interlocking intramedul ary nail (P<0.05). (3) In conclusion, in the distal femoral fracture fixation, the stiffness of the retrograde interlocking intramedul ary nail is low. While the LISS plate not only has certain deformation, but also has strong rigidity with firm internal fixation, which provides excel ent biological environment for fracture healing;thus it is a reliable treatment for distal femoral fractures.