Review Question - QID 219439

This patient presents after failing nonoperative management of tibiotalar and subtalar arthritis with talus avascular necrosis. The most appropriate treatment to improve pain and function is a tibiotalocalcaneal fusion.

Talar neck fractures are high-energy injuries to the hindfoot that can disrupt the blood flow to the talus. An increase in the Hawkins classification correlates with an increase in the incidence of avascular necrosis (AVN). Despite appropriate reduction and fixation, this patient has progressed to AVN of the talus with tibiotalar and subtalar arthritic changes. Even with appropriate non-operative treatment, many patients will experience significant pain and decreased function secondary to degenerative changes. The appropriate treatment plan for this resultant hindfoot arthritis depends on patient and anatomic factors. If the subtalar joint is spared and symptoms are isolated from the tibiotalar joint, a selective tibiotalar fusion can be performed. Ankle arthroplasty can also be considered in isolated tibiotalar arthritis; however, the patient needs appropriate bone stock in the talus. If the patient is symptomatic from subtalar and tibiotalar joints a tibiotalocalcaneal fusion is recommended, typically in the form of a hindfoot fusion nail. Patient factors also play a role in this decision-making process. The patient's functional goals and activity level must be factored into any surgical decision. As this patient has symptomatic arthritis in the tibiotalar and subtalar joint with AVN of the talus, the ideal treatment is a tibiotalocalcaneal fusion.

Tenebaum et al. reported on a retrospective case series of 14 ankle and hindfoot arthrodeses with a hindfoot fusion nail. Over 80% of the patients in this series had osteonecrosis involving the entire talus body. Non-structural bone graft was used in every case with 11 of the 14 cases using local autograft from the talus. The authors reported successful fusion in every case despite extensive talar AVN. The authors concluded that ankle and hindfoot arthritis with severe talus AVN can successfully be treated with a hindfoot fusion nail.

Backus et al. published an article reviewing arthrodesis options for the later stages of talar AVN. They defined the late-stage period as greater than 12 months. The authors reported that a tibiotalar arthrodesis is a good option for pain control in isolated symptoms with minimal talar collapse. At the same time, subtalar fusion is reasonable for isolated subtalar symptoms and no talar collapse. They reported on a novel 3-D titanium cage truss system that can be packed with bone graft or fusion adjuvants. Regardless of implant choice, the authors recommended tibiotalocalcaneal fusion in cases of combined tibiotalar and subtalar arthritis and talus AVN.

Figure A: Lateral plain film of an open Hawkins III talar neck fracture.
Figure B: Immediate postoperative film after irrigation and debridement of the open fracture with open reduction and internal fixation of the talar neck.
Figure C: Lateral plain film at 18 months post-op showing talar collapse, subtalar arthritis, with tibiotalar impingement and arthritis.

Incorrect Answers:
Answer 1: This patient has poor talar bone stock and concomitant symptomatic subtalar arthritis. Total ankle arthroplasty is not indicated in this setting and would not resolve all of his symptoms.
Answer 2: Tibiotalar fusion is indicated in isolated tibiotalar arthritis with minimal talar collapse.
Answer 3: Supramalleolar osteotomy would not address his arthritic symptoms and is not a salvage procedure with significant talus AVN.
Answer 5: Arthroscopic debridement is insufficient to address his significant arthritic changes.