[Dynamic forces of Mitkovic self-dinamysible trochanteric Internal fixators (SIF)]

Dynamic trochanteric fractures implants allow fracture fragments to be compressed. Dynamisation can be realized if the axial pin force overcome friction force between pin and body of the implant. Examination of sliding iniciation forces in Mitkovic Selfdinamysible Trochanteric Internal Fixator (SIF). SIF was attached for angle block in the position with vertical orientation of pins. The transversal load of 5 kg was connected to pins by a rope. A dynamometer was used to measure force during the movement of angle block in up direction. Regression coefficients were a1 = 4,052 i b1 = 0,623 for SIF with 2 sliding screws with diameter of 7mm and a2 = 4,534 i b2 = 0,422 for SIF with 1 screw with diameter of 10 mm. Coefficients of determination were: r12 = 0,470 and r22 = 0,123. Sliding of SIF pins can be achieved for each analysed body weight of patient (50-130 kg). Early bearing of operated leg is significant for sliding initiation of SIF sliding screws.