The difficult knee: severe varus and valgus.

To correct severe varus or valgus deformity, the surgeon must have clear knowledge of the location, orientation, and physical characteristics of the soft tissue structures that provide stability to the knee. Correct ligament balance restores proper load transfer across the knee and minimizes polyethylene wear. The failure to adequately release contracted ligaments or the overzealous release of ligaments will result in instability and secondary accelerated wear of a total knee implant. I describe several methods of selective ligament release of the contracted soft tissues that contribute to fixed varus and valgus deformity.