[Tibial realignment with external fixator]

External fixation is a proved method for high tibial osteotomies. It is easy to access, allows postoperative corrections of the alignment, and can be removed without additional narcosis. Disadvantages are the frequent infection of the pin tracks and discomfort in bearing compared to internal fixation. In our own study no difference between unilateral and bilateral fixation could be found regarding loss of correction and complications. The advantage of unilateral fixation is the possibility of doing an open-wedge procedure by unilateral continuous callus distraction (hemicallotasis). This is indicated if medial collateral instability can be compensated by the open-wedge technique. The occurrence of neural injuries was significantly less frequent after hemicallotasis. Regular radiological and clinical control of the axis is necessary to prevent loss of correction, which was significantly more frequent in open-wedge osteotomies.