Correction of tibial malunion in a patient with ipsilateral total knee and ankle prostheses using external ring fixation and the ilizarov method

Abstract

Total ankle replacement (TAR) aims at reestablishing a functional and painless ankle joint while maintaining motion and preventing adjacent joint arthritis. TAR can be complicated by comorbidities such as ipsilateral knee arthritis and deformity with subsequent arthroplasty and/or other lower extremity malalignment issues. We present a case of a 67-year-old female with severe right ankle pain and a history of ipsilateral subtalar and calcaneocuboid fusion, bilateral total knee arthroplasty, and a malunion of a conservatively treated ipsilateral segmental tibial fracture. Following TAR, there was recurrent lateral hindfoot pain due to subtle malalignment from the tibial malunion which resulted in persistent hindfoot valgus. This caused symptomatic subfibular impingement in addition to limb length discrepancy. To address that, a circular external fixator was applied to realign the ankle and lengthen the tibia, eliminating pain and avoiding complications with either implant.