Extensible interlocking intramedullary nail suitable for children

The extensible interlocking intramedullary nail comprises a hollow nail body of the intramedullary nail, the nail body is composed of an upper nail tube and a lower nail tube which are in butt joint in sequence, the lower portion of the upper nail tube extends into the lower nail tube, the lower portion of the upper nail tube is provided with a plurality of external threads, and the lower portion of the lower nail tube is provided with a plurality of external threads. Matched internal threads are correspondingly machined in the lower-section nail pipe and at the position of the external threads on the lower portion of the upper-section nail pipe, the upper end of the upper-section nail pipe is further provided with a wrench connecting portion, and nail holes are formed in the upper portion of the upper-section nail pipe and the lower portion of the lower-section nail pipe in the transverse direction. The problem that tibia development can be seriously affected when the existing intramedullary nail fixing oper