There are many difficult problems of reduction and its maintaining in the treatment of unstable intertrochanteric fractures. Especially, in cases of elderly patients with marked osteoporosis, prolonged immobilization brings more serious complication. In order to solve these problems, in cases of unstable intertrochanteric fractures with large lesser trochanteric fragment, we have carried out anatomical reduction and rigid internal fixation with compression hip screw and additional transfixation screw on posteromedial fragment. The unstable fractures have been convrted into the stable fractures by transfixation screw. We analyzed the 1 1cases with additional transfixation screw and they showed good results in one year follow up.