Locking plate fixationversus the third generation of the gamma nail fixation for intertrochanteric fractures：biomechanical stability / 中国组织工程研究

ABSTRACT

BACKGROUND:Being used in senile intertrochanteric fracture, the third generation of Gamma nail may isolate fracture fragments and it is difficult to be secured in the rotor, so the stability is poor. Varus deformity easily appears, which is difficult to support or satisfactorily reset. OBJECTIVE:To compare the effects and stability of the proximal femoral locking plate and the third generation of the gamma nail in the treatment of stable intertrochanteric fracture. METHODS:(1) A total of 64 patients with intertrochanteric fractures were respectively treated with the third generation of the gamma nail fixation (n=32) and proximal femoral locking plate fixation (n=32). Fracture reduction and healing were assessed using anteroposterior and lateral radiographs. Femoral rotor varus angle and intertrochanteric medial inclination received biomechanical measurement. (2) Eight femoral specimens whose shape and size were approximated were selected to be randomly assigned to Gamma 3 group and proximal femoral locking plate group (n=4), which respectively received Gamma 3 fixation and proximal femoral locking plate fixation. After axial compression test and destruction test, load-displacement curve was drawn. The maximum yield load value was calculated by torsion test. RESULTS AND CONCLUSION:Operative time and intraoperative blood loss were significantly more in the proximal femoral locking plate group than in the Gamma 3 group (P < 0.05). The fracture quality assessment results were better in the proximal femoral locking plate group than in the Gamma 3 group (P < 0.05). The axial stiffness and corresponding torque of various torsion angles were smaler in the proximal femoral locking plate group than in the Gamma 3 group (P < 0.05). Experimental results indicated that in the course of fixating intertrochanteric fracture merged with greater trochanter fracture, the proximal femur locking plate has obtained more biomechanical stability.