This invention in the field of orthopaedics and traumatology of medicine aims to provide lag screw applications with variable angles from the proximal hole of the femoral nails on elderly adult patients with femoral proximal fractures. Also; the present invention conforms to the intra-canal shape of the upper end of the femur (thigh bone) (trochanteric region) on the right, and the femoral neck, which can be different in diameter but of the same length, for the right and left upper ends of the femur that are inclined by this anatomy. It has been shown to obtain sufficient stability with the application of the nail inside the canal consisting of the fixing element holes and allowing a single fixing blade at different angles over a single nail compatible with the anteversion.