Apparatus for performing an open wedge, high tibial osteotomy, the apparatus comprising: cutting apparatus for forming an osteotomy cut in the tibia, the cutting apparatus comprising: targeting apparatus for identifying a cutting plane through the tibia and a boundary line for terminating a cut made along the cutting plane, wherein the boundary line is located within the tibia, parallel to the anterior-posterior slope of the tibia and parallel to the sagittal plane of the patient. A method for performing an open wedge, high tibial osteotomy, the method comprising: positioning targeting apparatus for identifying a cutting plane through the tibia and a boundary line for terminating a cut made along the cutting plane, wherein the boundary line is located within the tibia, parallel to the anterior-posterior slope of the tibia and parallel to the sagittal plane of the patient cutting the bone along the cutting plane, with the cut terminating at the boundary line moving the bone on either side of the cut apart so as to form the wedge-like opening in the bone and stabilizing the bone.
