The Internal Fixation Development Of Greater Tuberosity Fractures Of Humerus And A Biomechanical Contrast Study

Objective:By the biomechanical testing of the three different internal fixation techniques(hollow screws,tension banding wires, the internal fixation of greater tuberosity of the humerus) used for the treatment of greater tuberosity fractures of the humerus,the stability of comparing,to found a better fixator choose of biomechanics basis for the clinical application. Methods:To prepare 24 fresh frozen proximal humeri,standardized fratures of the greater tuberosity were maken,and randomly alloted the specimens to one of three group:hollow screws, tension banding wires,the internal fixation of greater tuberosity of the humerus.The specimens were respectively used to tractive testing.Then recorded two parameters:load to 2mm and 5mm displacement were metered in Newton(N).Then analyzed the experiments states by SPSS 19.0 software. Results:When loading to 2mm displacement of the greater tuberosity,the results of the three different internal fixations(hollow screws,tension banding wires, the internal fixation of greater tuberosity of the humerus)were:A=158.38±7.64N, B=168.27±4.70N, C=169.43±4.70N.By the results, the internal fixation of greater tuberosity of the humerus showed significantly higher values than two cancellous screws(P<0.05); There was no statistics difference with the internal fixation of greater tuberosity of the humerus and tension banding wires.(P>0.05); When loading to 5mm displacement of the greater tuberosity,the results were:A=349.77±31.79N, B=438.38±32.04N, C=506.26±10.13N. By the results, the internal fixation of greater tuberosity of the humerus showed significantly higher values than two cancellous screws and tension banding wires(P<0.01). Conclusion:This study indicated that the internal fixation of greater tuberosity of the humerus group had obvious biomechanical stability than two cancellous screws group and tension banding wires group. But the load to 2mm,5mm yield point was the most important parameter for clinical application.The internal fixation of greater tuberosity of the humerus group still showed better biomechanical superiority.To combine this research design of the internal fixation the clinical treatment curing the fracture of greater tuberosity of the humerus embodys all new and better project.