[The role of osteotomy in the therapy of the arthritic genu varum].

Abstract

The good results achieved with osteotomy in the treatment of arthritic varus knee lead the authors to pinpoint some frequently controversial aspects that are important for the attainment of an excellent outcome. The study consisted of 46 patients, each subjected to valgus osteotomy. The site of the tibial osteotomy should be above the insertion point of the patellar tendon in order to better guarantee stability and healing. For mechanical reasons, high metaphyseal peroneal osteotomy is preferred over other methods such as diaphyseal osteotomy, excision of the peroneal head, and proximal tibioperoneal syndesmotomy. Both osteotomies can be done through a single anterolateral incision, without risking injury to the lateral popliteal sciatic nerve. The preferred method of osteotomy is to cut a noncuneiform linear rima with the osteotome and perform the angular correction at the joint of the metaphyseal spongy bone. The osteotomy is then stabilized with staples and a cast for a period of 40 days. Overcorrection past the physiological valgus deformity is necessary in order to move the weight-bearing axis onto the lateral hemirima; the degree of surgical correction should be calculated on the basis of orthostatic radiographs. Good clinical results are always accompanied by the following radiographic developments: opening of the medial articular hemirima, improvement of the subchondral bone sclerosis, and reappearance of the outlines of both the spongy bone and the subchondral bone lamina; all these are signs of good bone adjustment made possible by the reinstatement of mechanical equilibrium in the knee.