Lower extremity angular malunion: evaluation and surgical correction.

The lower extremity has a mechanical axis with joint orientation that allows joint longevity and efficiency in bipedal gait. When normal alignment is lost because of trauma or other conditions, deviations from this anatomic norm may be deleterious to long-term joint function. In fractures that have healed with angular malunion, all facets of the deformity must be carefully considered, including alteration in length, rotation, alignment, and translation. Once all elements are fully defined, the effects of the malunion on mechanical axis and joint orientation can be understood. Techniques for surgical correction include wedge, dome, and oblique osteotomies and distraction osteogenesis. Each method possesses characteristics appropriate for certain clinical situations. Judicious patient selection and thoughtful preoperative planning may allow restoration of normal mechanics.