This work was aimed at evaluating, by means of a mathematical approachtint, the relationship between the resected bone wedge and the deformity to be corrected, and second the different tibial lengthening induced by close wedge or archiform osteotomy. We drew the following conclusions: 1) a mathematical equation was defined expresing an exact relationship between the bone wedge and the angular correction; 2) the metaphysical widening has been found to be a relevant factor conditioning the angle of the bone wedge; 3) core wedge osteotomies induce a shortening of the tibia which is compensated by the correction of the axis; 4) Archiform osteotomies do not modify tibial length but produce an apparent limb lengthening when correcting the axis of the extremity.

This work was aimed at evaluating, by means of a mathematical approachtint, the relationship between the resected bone wedge and the deformity to be corrected, and second the different tibial lengthening induced by close wedge or archiform osteotomy. We drew the following conclusions: 1) a mathematical equation was defined expresing an exact relationship between the bone wedge and the angular correction; 2) the metaphysical widening has been found to be a relevant factor conditioning the angle of the bone wedge; 3) core wedge osteotomies induce a shortening of the tibia which is compensated by the correction of the axis; 4) Archiform osteotomies do not modify tibial length but produce an apparent limb lengthening when correcting the axis of the extremity.