Lower Limb Deformity Correction: Analysis and Preoperative Planning.

Lower limb deformities have a wide range of presentations and require significant preparation and planning from the surgeon to correct. It is important to provide a clear and systematic approach to preoperative planning for these cases and to detail three well-established correction techniques: external fixation, plate fixation, and intramedullary nail fixation. In using a simple mnemonic that lays out the systematic analysis of various axis lines and joint angles from proximal to distal in the lower extremity, deformities can be readily identified, and correction strategies can be effectively used to produce a successful deformity correction that restores colinear alignment to the lower limb. Additional pearls and pitfalls for these techniques are also provided to assist with some of the nuances that exist in the field.