Mechanical axis deviation of the lower limbs. Preoperative planning of multiapical frontal plane angular and bowing deformities of the femur and tibia.

Multiapical deformities complicate the process of preoperative planning. It is necessary to determine the level of each apex of deformity to plan accurate correction. The basic principles of mechanical axis realignment and joint orientation need to be preserved. Using the joint reference lines and mechanical axis of each bone segment, one can accurately determine the apex of each deformity. Bowing deformities are multiapical angular deformities. There are two types of bowing deformities: compensated and noncompensated. Typical examples of compensated bowing are the anterolateral and posteromedial bows of the tibia. A noncompensated bow is typical of the deformity seen in rickets.