summary Ankle arthrodesis is the fusion of the tibiotalar joint most commonly performed for end-stage arthritis of the joint. The procedure may be performed with an open approach or arthroscopically. The most common complications are development of subtalar arthritis and nonunion. Indications Indications painful arthritis following infection trauma (most common cause) chronic instability AVN of the talus inflammatory arthropathy primary OA neuropathic arthropathy tumor resection salvage for failed ORIF salvage for failed TAA Technique Optimal Position neutral dorsiflexion 5-10° of external rotation 5° of hindfoot valgus 5 mm of posterior talar translation Arthroscopic arthrodesis only indicated if minimal deformity present Open arthrodesis transfibular approach often used when deformity present screw fixation plate and screw construct external fixation fusion of the talonavicular joint decreases hindfoot ROM >90% staged approach infection should be cleared prior to placement of definitive internal hardware for arthrodesis Tibiotalocalcaneal (TTC) fusion with retrograde intramedullary nail Load-sharing device with improved bending stiffness and rotational stability compared to plate-and-screw constructs Indications: End-stage ankle and subtalar arthritis Charcot neuroarthropathy Significant hindfoot bone loss (failed total ankle arthroplasty, failed arthrodesis) Osteonecrosis of the talus lateral transfibular approach allows for dual joint preparation as well as local autograft Severe acute trauma Contraindications: Active infection Profound vascular disease Severe tibia malalignment Complications Nonunion incidence 10% non union rate tobacco users have 2.7x risk neuropathy is greatest risk factor for persistent nonunion with revision of nonunion Lateral plantar nerve injury Superficial peroneal nerve injury to superficial peroneal nerve during transfibular approach Hindfoot arthritis adjacent hindfoot arthritis commonly occurs following fusion isolated hindfoot arthritis due to chronic pes planus is treated with subtalar joint arthrodesis