Biomechanical Considerations in Rearfoot Fusions.

This article discusses rearfoot fusions for foot and ankle surgeons. It establishes normal foot and ankle function primarily in the stance phase of gait. The foot is greatly affected by external and internal forces, which contribute to normal function or the need for compensatory mechanisms. As a result of compensation, many symptoms develop, often leading to debilitating disorders such as degenerative joint disease. The interaction of the ankle, subtalar, and midtarsal joints are outlined. Congenital deformities, trauma and abnormal compensation are reviewed along with corresponding sequelae. Surgery is often indicated to reduce symptoms, improve position, and help stabilize the foot.