BACKGROUND:Anti-rotation intramedulary nail fixation for proximal femoral fractures replaces the femoral bearing axis, moves towards body axis relative to hip screw and dynamic ankle screw, enhances the anti-fatigue strength at the fracture site, supports the anti-varus and prevents the rotation of the proximal fracture site, and is suitable for the treatment of unstable fracture. OBJECTIVE:To comparatively observe the effects of dynamic hip screw knife system and minimaly invasive spiral blade anti-rotation intramedulary nail in the repair of unstable intertrochanteric fractures. METHODS: A total of 82 cases of unstable intertrochanteric fractures, who were treated in the Department of Orthopedics, First People’s Hospital of Shunde from January 2012 to January 2014, were selected in this study. The patients were equaly and randomly divided into two groups: dynamic hip screw knife system group and minimaly invasive spiral blade anti-rotation intramedulary nail group. Repair index, fracture healing time and the incidence of complications were compared between the two groups. RESULTS AND CONCLUSION:Healing time and repair index were significantly better in the minimaly invasive spiral blade anti-rotation intramedulary nail group than in the dynamic hip screw knife system group (P < 0.05). Complications appeared in five patients from the minimaly invasive spiral blade anti-rotation intramedulary nail group, with the incidence rate of 12%, and in ten patients from the dynamic hip screw knife system group, with the incidence rate of 24%. The incidence of complications was significantly lower in the minimaly invasive spiral blade anti-rotation intramedulary nail group than in the dynamic hip screw knife system group (P < 0.05). These data suggest that for patients with unstable intertrochanteric fracture, minimaly invasive spiral blade anti-rotation intramedulary nail can decrease the incidence of complications, elevate the safety of the repair method, and promote the functional recovery.