| A new kind of internal fixture, Intramedullary expand Self locking Nail(IESN), was applicated, which was easy to be used ion for tibial fractures. In order to provide experiment and clinical data for safe clinical practice, this study aimed to evaluate Intramedullary expand Self locking Nail for tibial fractures.there parts comprised in this paper.In the first part of this study, the biomechanical tests of Intramedullary expand Self locking Nail for tibial fractures were evaluated in vitro, includind tensile strength test and fatigue test. Objective: Tibial fractures fixed by Intramedullary expand Self locking Nail(IESN) were tested for the sake of understanding their biomechanical. Methods The rigidity of tibial fractures fixed by the lESNs was compared with that of fractures fixed by intramedullary interlocking nails and Meihua nails in the auti-torsional rigidity,the auti-bending rigidity.the auti-axial tensile test and the fatigue test.in the experiment, 18 pieces of flesh tibias were used. Results the torsional rigidity , bending rigidity, axial tensile rigidity of IESN were superior to the Meihua nails (p<0.01). the torsional rigidity of intramedullary interlocking were little superior to IESN (p > 0.05), bending rigidity, axial tensile rigidity of IESN were equal to intramedullary interlocking (p<0.01). Conclusionthe IESN had fine biomechanical characteristics in fixation for tibial fractures,especially in auti-axial tension and bending.The second part of this study is finite element analysis of Intramedullary expand Self locking Nail. Objective:ln order to analysis the tensile strength of Intramedullary expand Self locking Nail and the distribution of tensile stress in it when it is in state of tension with the finite element method(FEM). Methods: The scanning image of Intramedullary expand Self locking Nail and its material property were input into the inherent coordinate of ANSYS in which the FEM model was reconstructed. The model was extended with restriction on different place and analysed. The tensile strength on the Intramedullary expand Self locking Nail model and the distribution of tensile stress in it was calculated.Results:When the Intramedullary expand Self locking Nail was fixed, the two tips of its tensile stress was more on the Intramedullary expand Self locking Nail, the pull is about 380 newton. ConcIusions:The tensile strength of Intramedullary expand Self locking Nail is enough strong; the middle of Intramedullary expand Self locking Nail is the concentrated part of tensile stress and is apt to collapse when fatigue alternating stress acts on it.The third part of this study is clinical application of Intramedullary expand Self locking Nail for tibial fractures. Objective: To report the clinical experience intreating tibial fractures with Intramedullary Expanded Self-locking Nail (IESN),in order to improve its effect of the appliance .Methods: From 1998 to 2003,47 patients with the fractures of tibial were treated with intramedullary expanded self-locking nail, 39fractures were fresh in the median ,median third and lower third of the tibial.The remaining 8 were old fractures, of which 6 were in the median.and 2 in the lower third (4 Splintered fracture, 2 transverse fracture).AH fractures were closed, used intramedullary expanded self-locking nail was from upper to lower. Results: All patients were followed-up form 8 to 48 months. 45 of the fixed in theintramedullary expanded self-locking nail were healed. Conclusion: intramedullary expanded self-locking nail can be used as an effective method to treat tibial fracture with the advantages of simple procedure,minimal invasion,stable fixation and early weight bearing. |
