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Objective: distal humerus fractures in adults is relatively rare, accounting for 2% of all fractures, it is a very challenging fractures for its treatment. Complex three-dimensional geometry of the distal humerus fractures of the distal humerus fixed a considerable challenge. In the early 20th century, primarily through the braking treatment of distal humerus fractures, most of the patients with poor efficacy. Early surgical treatment options not firmly fixed, after long-term braking effect is not ideal. Since the AO organization fracture ORIF this important concept, internal fixation has become the \Anatomic reduction, strong fixation and early postoperative functional exercise is very important for the treatment effect of distal humerus fracture surgery. In order to improve the therapeutic effect, people design a variety of fixed program. Currently, the most widely accepted is the vertical double plate fixation, the reason behind the lateral column of the distal humerus articular surface anatomy suitable placed steel plates, more importantly, is a vertical double plate fixation strength. However, this method of fixing its inadequacies, peel the soft tissue of the distal humerus requires extensive surgery, the need to pre-ulnar nerve, after easily lead to nonunion, ulnar nerve paralysis and other complications. Distal humerus fractures fixed not an ideal method, still we need to actively explore more desirable fixed. Used in clinical improvement golf plate fixation of distal humerus fractures achieved very good results, yet this regard biomechanics research, however, based on the purpose of our design of the experiment used to evaluate the improved golf steel plate with vertical double plate biomechanical stability of the treatment of distal humerus fractures, discover a new treatment of distal humerus fracture fixation methods. : 1 Specimen 10 adult full cadavers (male 6, female 4; Age: 45 to 73 years, average age, 56.5 years) all in 10% formalin preservative treatment for system anatomy research purposes. All specimens were not humerus fracture history, no history of connective tissue disease or hemiplegia. Remove 10 of the humerus, stripped clean of soft tissue, leaving only the bony structure. All specimens were recognized by the naked eye and X-rays, no deformity, osteoporosis and other abnormalities. Numbered 10 of the humerus, and two from the same corpse on the humerus specimens were randomly divided into Group A, Group B, set the self-control, but also to ensure that the two sets of specimens in age, gender, bone quality does not appear significant difference. Two pairs of golf steel plate the angle holes improved removal of the proximal end of the golf steel plate and shaping them to adapt to the the posterolateral distal humerus anatomical structure and the corners sanded smooth (Fig.1, 2). The upper edge of the 3 Preparation of experimental models along the olecranon bone saws artificially made rampant fracture (AO: 13 - A2.3), the fracture line at 5mm thick spacer separated reset fractures 2.0mm Kirschner temporary fixed . The improved golf steel plate fixed by a surgical experience with surgery completed, use special surgical instruments and fixed; 7 holes, 8 holes, general reconstruction plate shaping it to adapt to the humerus posterolateral medial anatomical structure, and fastened with screws Similarly, the vertical double-plate fixation are done with an experienced surgeon, followed by removal of the humeral head bone saw, and the cross-section perpendicular to the axis of the humerus, CR X line Machine recognized the screw position accuracy (Fig.3), and finally removing Kirschner, spacer, made the final experimental model (Fig.4, 5). The number of screws used two fixed methods (Table 1). 4 experimental methods will be in contact with the biomechanical machine articular surface coated with resin to prevent stress too concentrated, damage to the articular surface [1]. Each of the experimental model should be subjected to flexion, extension, axial load tests (Fig.6, 7,8). Stress load biomechanics machine sustained rate 5mm/min. Fixation failure criteria: ① fixture is damaged or (2) screw - bone contact surface is loose or ③ screw from bone prolapse or ④ 5mm gap closed the gap both ends of the bone contact. Measure and record the maximum load (Table 2). 5 Statistical analysis application SPSS16.0 the (statistical products and services solutions) and B two sets of data for comparison of two independent sample Wilcoxon rank sum test (p ≤ 0.05 statistically significant). Results: axial load test maximum number: Group B Group A 121.7 ± 14.7 (N); 157.0 ± 16.4. Group A can withstand axial load difference in Group B (p = 0.01, p lt; 0.05) was statistically significant; The the flexion load test maximum number: Group A 110.4 ± 8.8; Group B 79.5 ± 7.1 A The flexion group can bear load was significantly greater than Group B, (p lt; 0.01) was statistically significant. Mean maximum extension load test: Group A 101.0 ± 7.9; Group B 95.5 ± 12.4, the extension load with Group B Group A can withstand considerable (p = 0.24, p gt; 0.05) was not statistically significant ( Fig.12, 13,14). Conclusion: Biomechanical Experimental results show that: the biomechanical stability with vertical double plate fixation systems are quite fixed distal humerus fractures using a modified golf plate system. The improved golf plate is a fixed distal humerus fractures.
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