The invention is a device consisting of a new Kirschner wire guide, `U` shaped osteotomes, angle-scale distractor and a height conserving support wedge application device for use in medial opening wedge high (proximal) tibial osteotomy surgeries. The utility model file on the subject has been shared. With the Kirschner wire guide designed, the osteotomy line can be determined using fluoroscopy in the least amount of time. The cutting of the contralateral (lateral) cortex was prevented by `U` shaped osteotomes. Intraarticular fractures in the lateral tibial plateau and fractures in the contralateral cortex were prevented by performing controlled distraction with an angle-scale distractor. The distraction amount can be measured from the angle-scale of the distractor. Plate can be applied by preserving the distraction made with height protective wedges.