Periprosthetic Fracture of the Talus following Total Ankle Replacement: A Case Series

CATEGORY: Ankle; Ankle Arthritis; Trauma INTRODUCTION/PURPOSE: Although total ankle replacement (TAR) for the treatment of end-stage ankle arthritis has been shown to have excellent radiographic and clinical outcomes, there is a risk for complications such as periprosthetic fractures. While periprosthetic fractures of the tibia are well described in the literature, little is known about such fractures involving the talus. The purpose of this case series is to describe the radiographic findings and surgical management of talar fractures sustained after placement of total ankle prostheses. METHODS: We retrospectively reviewed 489 patients who underwent total ankle replacement from June 2015 to March 2019, and identified five cases (2 males, 3 females, average age 45.7 years) in which patients sustained a periprosthetic fracture of the talus. All patients presented symptomatically with ankle pain during postoperative follow-up, and fractures of the talus were confirmed on computed tomography (CT) imaging. One patient had psoriatic arthritis and four patients had primary osteoarthritis of the ankle. CTs were reviewed to confirm location and pattern of the fracture, as well as related pathology such as osteolysis and subsidence. Hospital charts and operative reports were reviewed to record patient demographics and postoperative management including reoperations. RESULTS: Overall the incidence of talar fractures was 1% (5/489) and all occurred in implants with a talar stem (4 INBONE II, 1 Salto Talaris). All fractures extended from the stem of the talar component into the subtalar joint, with one case of a non- displaced fracture. Osteolysis surrounding the talar stem was observed in all cases, with subsidence of the talar component observed in four out of five patients on CT. All five patients presented symptomatically and underwent reoperation (1 revision of talar component with ORIF, 3 subtalar fusions, 1 tibiotalar fusion). CONCLUSION: The findings in this case series suggest that periprosthetic fractures of the talus following total ankle replacement is a possible complication of stemmed implants and is associated with poor clinical outcomes requiring reoperation. Therefore, a periprosthetic fracture of the talus should be considered in a patient with unexplained pain and evidence of radiographic osteolysis around the stemmed component.