The presented article is an original contribution which implies the design of a specialized device for high tybial osteotomy (HTO) optimization. In the papers are presented the sources that imply HTO, the axial deviations of the human lower member from the correct position. This sources are the gonarthosys owed to the usage of the knees cartilages or owed to some diseases (such as the Blount disease) and the vicious consolidated fractures. After presenting the needs to realize such a specialized device for HTO, the principal requests the device shall fulfill are underlined. Starting from these , two sub ensembles were projected, one for the tibial positioning and for the execution of the hole from the center of rotation of angulation (CORA), and the second one for the realization of the cuts. Both sub ensembles have been 3D modeled in Catia V5R20. The model was designed mounted on the bone.
