Femoral osteotomies for the valgus knee

Lower limb alignment is an important contributing factor to the development of knee arthritis, and it is related to the articular cartilage wear pattern (1). Osteotomies around the knee are a well-recognized treatment for symptomatic unicompartmental knee arthritis associated to lower limb malalignment in young and active patients, with the attempt to preserve the native knee joint and delay knee arthroplasty (2,3). Genu varum is the most common knee malalignment, and good results have been described in literature for high tibial osteotomy (HTO) performed to treat medial unicompartmental knee arthritis in varus malalignment (4). Valgus malalignment is less common compared to varus malalignment. Excess of physiological valgus (5°–8°) leads to mechanical overload of the lateral compartment, increasing the risk of lateral knee osteoarthritis development. Valgus deformity can be idiopathic or secondary to other pathologies (i.e., metabolic disorder, rheumatoid arthritis, rickets, poliomyelitis) or to a previous lateral tibial plateau fracture (5). Some authors performed proximal tibial osteotomy to correct the valgus deformity but unsatisfactory results have been reported (6). This is probably because valgus deformity is often associated with hypoplastic lateral femoral condyle and with a joint line that slopes from superolaterally to inferomedially in the anterior-posterior plane. This deformity cannot be corrected unless the osteotomy is performed proximally to the joint (6,7). Coventry, in 1973, established that if valgus deformity is greater than 12° or if the joint plane deviate more than 140° from the horizontal one, a distal femoral osteotomy (DFO) should be performed rather than an HTO to correct the deformity (3). Review Article