The effect of different pin configurations on cyclic stability in pediatric proximal humerus fracture fixation: A Sawbones model study.

Abstract

In sawbones with proximal humerus fracture model, three different fixation configurations, Parallel-Straight K-wires, Cross-Straight K-wires and Palm-Tree Method, were biomechanically compared. A total of 36 anatomical pediatric humerus sawbones models were used. They were divided into three equal groups; parallel fixation with straight K-wires (Group PS), cross fixation with straight K-wires (Group CS), and Palm-Tree Method (Group PT). Models were tested in abduction and torsional at a speed of 0.5 mm/s and a 0-5 mm displacement range. Loading (N) and Stiffness (N/mm) data were calculated and compared statistically. Group PS was significantly higher than the other two groups in abduction bending cyclic load values (P<0.001). It was also significantly higher in Group CS than in Group PT (P < 0.001). No significant differences were detected between the three different fixation groups' cyclic torsional load values (p < 0.05). The parallel configuration with straight K-wires will provide a more stable fixation than the cross configuration with straight or Palm-Tree Method in pediatric proximal humeral sawbones fracture modeling.