Are We Ready for Pseudotumors in Total Ankle Arthroplasty? A Case Report

Background: Pseudotumors are defined as exuberant non-neoplastic inflammatory masses. This condition can be associated with hip and knee arthroplasty but has not been reported in Total Ankle Arthroplasty (TAA). This paper reports a pseudotumor that formed following TAA, highlighting its clinical presentation, management, and histopathology. Methods: A 55-year-old male with end-stage post-traumatic ankle osteoarthritis underwent TAA using a mobile-bearing prosthesis. The procedure was reported to be successful, with no immediate complications. Results: Three years postoperatively, following a period of symptom resolution, the patient presented with progressively worsening ankle pain, swelling, and limited weight-bearing ability. Imaging revealed indirect signs of a periarticular mass and loosening components. Revision surgery involved prosthesis explantation and mass excision for histological and microbiological analysis, followed by concomitant tibio-talo-calcaneal fusion with a retrograde nail. The histopathology identified a pseudotumor characterized by chronic inflammation, fibrous tissue, and necrotic debris, with no evidence of infection. The postoperative recovery was uneventful, with pain resolution and successful fusion confirmed at a one-year follow-up. Conclusions: In patients experiencing unexplained pain or symptoms following TAA, the possibility of a pseudotumor, although rare, should be considered. Prompt and comprehensive clinical and radiographic evaluation is crucial to raise suspicion and prevent this condition from being overlooked.