Despite appropriate acute treatment, many foot and ankle injuries result in posttraumatic arthritis. Arthrodesis remains the mainstay of treatment of end-stage arthritis of the foot and ankle. An understanding of the biomechanics of the foot and ankle, particularly which joints are most responsible for optimal function of the foot, can help guide reconstructive efforts. A careful history and physical examination, appropriate radiographs, and, when necessary, differential selective anesthetic blocks help limit fusion to only those joints that are causing pain. Compression fixation, when possible, remains the treatment of choice. When bone defects are present, however, neutralization fixation may be necessary to prevent a secondary deformity that could result from impaction into a bone defect.