The primary indication for subtalar arthrodesis is painful arthritis. Common causes of arthritis include osteoarthritis, posttraumatic arthritis, and arthritis from inflammatory diseases. These etiologies may cause alterations in the normal foot alignment—an important consideration in preoperative planning. For example, a severe valgus alignment associated with posterior tibial tendon insufficiency must be corrected in addition to the goal of obtaining an arthrodesis. Surgical treatment is considered after nonsurgical treatment—such as cortisone injections, medications, inserts, and rocker-bottom shoes—has failed.