Tabetic Arthropathy as an Uncommon Cause of Destructive Joint Disease: A Case Report

Tabetic arthropathy is a destructive neurogenic joint disease that has become rare due to the early treatment of syphilis with penicillin G. It results from neurosyphilis caused by Treponema pallidum. The diagnosis is suspected in patients presenting with severe joint destruction disproportionate to the absence or minimal intensity of pain and is confirmed by positive syphilitic serological tests. We report the case of a 62-year-old patient with a history of high-risk sexual behavior and a remote episode of cervical lymphadenopathy treated 40 years ago. He presented with chronic painless monoarthritis of the right knee, without fever, associated with elevated inflammatory markers. Knee radiography revealed destruction of the medial tibial condyle, while magnetic resonance imaging (MRI) demonstrated osteolytic lesions of the medial tibial plateau with bone fragment detachment. The diagnosis of tabetic arthropathy was confirmed by positive syphilis serology. The clinical course was favorable following appropriate treatment, with marked clinical and biological improvement. Although exceptional, tabetic arthropathy should be considered in cases of painless destructive arthropathy. Treatment is primarily based on intravenous penicillin G, with third-generation cephalosporins as an alternative when penicillin is unavailable.