Diagnostic pitfalls in the imaging of talar aseptic osteonecrosis in children: Osteoarticular tuberculosis mimicking avascular necrosis of the talus: A case report

Background: Osteonecrosis-like radiological images of the talus are uncommon in children. When encountered, they should prompt a systematic search for an underlying aetiology, including osteoarticular tuberculosis (OAT), which remains the leading cause of talar osteolytic lesions in high-prevalence regions.
Case Presentation: We report the case of a 12-year-old girl with no significant past medical history who presented with a two-year history of antalgic gait and progressive right ankle swelling, associated with constitutional symptoms (low-grade fever and night sweats). Plain radiography revealed an osteolytic geode-like lesion of the talus without periosteal reaction; CT scan confirmed mirror-image osteolytic lesions of the talus and the distal tibia. Surgical exploration disclosed pus, caseous material and a destructive lesion at the talar neck. Histopathological analysis of bone biopsy specimens confirmed necrotising tuberculoid granulomatous inflammation. The patient completed nine months of standard anti-tuberculous therapy (RHZE/RH) with satisfactory clinical and radiological outcome.
Conclusion: Isolated talar tuberculosis is a rare but important differential diagnosis to consider in children presenting with chronic ankle pain and swelling in endemic settings. Awareness of its imaging similarities to avascular necrosis is essential to avoid delayed diagnosis and unnecessary procedures. Histopathological confirmation remains the gold standard for diagnosis, and early anti-tuberculous treatment leads to favourable functional outcomes.