Review Question - QID 213942

The patient is presenting with persistent and worsening ankle pain since a total ankle arthroplasty (TAA). Given the bone loss and history, a work-up for infection is necessary.

TAA is an alternative treatment option to ankle arthrodesis for end-stage tibiotalar arthritis that preserves range of motion and can potentially increase cadence speed compared to fusion. Potentially devastating complications include deep infections and implant loosening with osteolysis. In the setting of a painful arthroplasty, the ideal treatment option would be a revision ankle arthroplasty, as there are poorer outcomes with secondary fusion, but is dependent on sufficient bone stock, range of motion, and adequate soft tissue coverage. Initial work-up for a painful TAA should include inflammatory markers and complete blood count to evaluate for a chronic infection, as this would change management to an antibiotic spacer followed by reimplantation or fusion.

Hsu et al. reviewed the evaluation and management of the painful total ankle arthroplasty. They stated that surgical options for failed total ankle arthroplasty are revision ankle arthroplasty, arthrodesis, and amputation. Arthrodesis following a failed total ankle arthroplasty is associated with worse outcomes than primary arthrodesis, therefore the authors prefer revision arthroplasty when there is sufficient bone stock, adequate soft tissue coverage, sufficient range of motion, and patient compliance with early ambulation. Patients who fall out of this category are better managed with a secondary arthrodesis.

Berkowitz et al. performed a retrospective study of failed total ankle arthroplasties converted to either isolated tibiotalar or tibiotalar-hindfoot fusions. They reported a significant improvement in the American Orthopedic Foot & Ankle Society scores following isolated tibiotalar fusion. There was one case of nonunion following isolated tibiotalar fusion, whereas five cases involving the subtalar joint with ankle-hindfoot fusion, which was statistically significant. The authors concluded that failed ankle arthroplasty can be successfully treated with an ankle fusion, and cases of subtalar nonunion can be minimized with a separate surgical approach to prepare the subtalar joint.

Figures A and B are the AP and lateral radiographs of the right ankle with a TAA prosthesis and ballon osteolysis near the tibial component and apparent subsidence of the talar component. Figures C-F are the coronal and sagittal CT scans of the right ankle with extensive bone loss around the tibial component without the presence of subtalar arthritis.

Incorrect answers:
Answer 1: A two-stage revision would be the treatment of choice if there is an established infection.
Answer 2: A one-stage revision would be ideal if there is a preserved range of motion with sufficient bone stock. In this case, the patient has a large degree of bone loss around the tibia that may or may not be salvageable with bone grafting and a revision long-stemmed prosthesis.
Answer 3: Tibiotalar arthrodesis can be a good salvage procedure in the setting of extensive bone loss, but preserved talar bone stock and lack of subtalar arthritis.
Answer 5: Combined tibiotalar and subtalar arthrodesis can be a salvage procedure in the setting of extensive bone loss with insufficient talar bone stock remaining or with the presence of subtalar arthritis.