Interest of targeted computed tomography guided by scintigraphy in the diagnosis of an osteoid osteoma of the talus: A surgical case report.

INTRODUCTION AND IMPORTANCE: Osteoid osteoma is a benign primary bone tumor with a predilection for the long bones and vertebrae, presenting a unique challenge when occurring in rare locations such as the talus, accounting for 5 to 8 % of cases. Early imaging struggles to detect its nidus, leading to diagnostic delays, especially when atypical symptoms and previous trauma complicate clinical presentations. This case report illustrates the diagnostic challenges and emphasizes the importance of targeted computed tomography (CT) guided by scintigraphy in diagnosing osteoid osteoma of the talus. CASE PRESENTATION: A 23-year-old male presented with chronic left ankle pain spanning three years, with a history of previous trauma. Initial evaluations including standard radiology and magnetic resonance imaging (MRI) suggested algodystrophy of the talus and tenosynovitis, but failed to identify the osteoma. Persistent pain led to further investigation with bone scintigraphy, revealing hyperfixation indicative of partial algodystrophy. Targeted CT scans focused on the scintigraphy-identified area ultimately revealed an osteoid osteoma's nidus, enabling successful surgical intervention and symptomatic relief. DISCUSSION: The diagnosis of osteoid osteoma in the talus is frequently delayed due to its atypical presentation and rare occurrence. Traditional imaging techniques may overlook the tumor's nidus, underscoring the necessity for targeted diagnostic approaches. This case demonstrates the value of integrating scintigraphy with targeted CT to enhance early diagnosis and treatment planning, contrasting with the limited diagnostic yield of MRI and underscoring CT's superiority for nidus detection. CONCLUSION: Osteoid osteoma of the talus poses significant diagnostic challenges. This case report highlights the utility of scintigraphy-guided targeted CT in identifying the nidus and facilitating prompt surgical management, advocating for a multidisciplinary approach to atypical ankle pain, especially in patients with a history of trauma.