A knee brace for the correction of abnormalities of the knee such as varus or valgus knee, or for the various forms of osteoarthritis, consisting of a support structure with a sole direction of development, that is to say it comprises a single upright (11) for the femoral area and a single upright (12) for the tibial area, these uprights (11, 12) being connected and hinged to a single articulated joint (13), which can be positioned close to one side of the knee, generally the outer side in the case of varus knee or the inner side in the case of valgus knee.