Tumor type knee joint prosthesis intramedullary needle

The invention discloses a tumor type knee joint prosthesis intramedullary needle which comprises a thighbone intramedullary pin lower segment, a thighbone intramedullary pin upper segment and a self-adaptive part. The thighbone intramedullary pin lower segment and the thighbone intramedullary pin upper segment are inserted into the thighbone marrow cavity during an operation. The self-adaptive part enables the thighbone intramedullary pin lower segment and the thighbone intramedullary pin upper segment to be connected and enables the intramedullary needle to have a certain rotating freedom degree. The self-adaptive part comprises a self-adaptive bearing column at the end of the thighbone intramedullary pin upper segment, an inner pin hole in the self-adaptive bearing column, an outer pin hole in the side wall of the end of the thighbone intramedullary pin lower segment and a self-adaptive bearing cone hole in the end of the thighbone intramedullary pin lower segment, and the self-adaptive bearing column can be inserted into the self-adaptive bearing cone hole. A pin capable of being inserted into the outer pin hole and the inner pin hole is further included. The intramedullary needle can adapt to the physiological curvature that the thighbone is upward outside, inclined and downward inside, and the technical problem that the thighbone and the prosthesis lateral force line are not matched due to the fact that an existing artificial knee joint prosthesis intramedullary needle is inconsistent with the thighbone anatomic form can be solved better.