This invention regarding the nail inside the medulla being the invention, using for the especially tibia, to inside the medullary cavity being inserted is suited for the proximal end which (2), the end mount (3) and to be formed with the center shaft (6), as for the nail inside the aforementioned medulla, A) the range the total length L 200 - 500mm possessing B) 1st bend as for (4) length G1 =L and curve radius R1 possessing C) the 2nd bend (13) length G2 =G1 and curve radius R possessing2