Experimental Study Of The Internal Fixation Of Modified Wiring On Treating Fracture Of Olecranon And Its Clinical Application

Objective: To evaluate the rigidity of figure-eight and circular wiring (î–‰W)compared with the other four common techniques of internal fixation, meanwhile to probe into their biomechanical effect, then to search the ideal and practical way of internal fixation of olecranon fracture, which can provide experimental data in selecting the internal fixation, then testify and guide the clinical treatment of olecranon fracture.Methods: Ten male adult cadaveric elbow joints remained with the triceps tendons attachment on the olecranon besides the articular caspule of elbow were made into transverse, oblique and comminuted fracture osteotomies. Each model in 90 degree flexion was fixed on the WWL-100B all-purpose electronic machine of experiment. The movement of fracture sited with a acute displacement transducer to the ulna was tested in five techniques of the internal fixation namely: circular wiring, figure-eight wiring, ECW, Kirschner tension band and the screw. Then, the relation of load-strain and division regulation of the stress about olecranon fracture were studied. The maximal failure load of each specimen of internal fixation was tested at last. In clinical application,twenty-six patients of olecranon fracture treated with ECW were observed.Results:1. The comminuted fracture model of olecranon was the most instable, and the difference about stability between transverse fracture model and oblique fracture model was not significant (P>0.05).2. The rigidity of internal fixation of the circular wiring was the smallest, figure-eightwiring was similar to the screw, ECW was better than the figure-eight wiring or the screw(P<0.05).3. There was no significant difference between ECW and Kirschner tension band at transverse and oblique fracture models(P>0.05),but ECW overmatches Kirschner tension band at comminuted fracture modeI(P<0.05).4. The extreme load of the circular wiring was the smallest (35.68 +2.37), Kirschner tension band was best(83.75+2.66N), but there was no significant difference between ECW and Kirschner tension band(P>0.05).5. Twenty-six patients of olecranon fracture treated with ECW were followed up with a period of 3 to 13 months. None of them was non-union, and 92.30% of them were excellent and good.Conclusion:1. The comminuted fracture model of olecranon was the most instable, and the difference about stability between transverse fracture model and oblique fracture model was not significant.2. The rigidity of internal fixation of the circular wiring was the smallest, figure-eight wiring and the screw gave little reliable result, ECW was better than them.3. There was no significant difference between ECW and Kirschner tension band at transverse and oblique fracture models, but the rigidity of ECW was superior to Kirschner tension band at comminuted fracture model.4. From the experimental study and clinical application, because of its reriable fixation, easity to insert and less damages, we are sure that ECW is the ideal choice of the internal fixation of the olecranon fracture at most kinds of fractures, especially for comminuted fracture to some extent, and is deserved to be applied widely.