The present invention relates to a bone plate internal fixator device (101； 501； 701) for epiphysiodesis, comprising a pair of holding elements (102, 103； 502, 503； 702, 703), each one of the holding elements (102, 103； 502,503； 702, 703) respectively comprising a through hole (104, 105； 504, 505； 704, 705) configured for receiving a respective fixing screw (301) to a bone； the bone plate internal fixator device (101； 501； 701) further comprises a central portion (106； 506； 706) which structurally connects and constrains the holding elements (102, 103； 502, 503； 702, 703) with each other； the central portion (106； 506； 706) is flexible so as to allow flexing of the bone plate (101； 501； 701)； each said through hole (104, 105； 504, 505； 704, 705) comprises a threaded surface (108, 109； 508, 509； 708, 709) adapted to couple with a corresponding surface (304) of the respective fixing screw (301)； the holding elements (102, 103； 502, 503； 702, 703) and the central portion (106； 506； 706) are provided as a composite structure.
