Pathological Fracture of Thoracic Spine Aneurysmal Bone Cyst: A Case With Successful Outcome Following Debulking, Posterior Instrumentation, and Allogenic Bone Impaction Grafting

Aneurysmal bone cysts (ABCs) are benign, osteolytic lesions characterised by blood-filled spaces separated by fibrous septa. Although benign, ABCs exhibit locally aggressive behaviour, leading to significant bone destruction. These cysts primarily affect children and young adults, often occurring in the metaphysis of long bones and the spine. Spinal ABCs are particularly concerning due to the potential for neurological deficits caused by spinal cord compression. The pathogenesis of ABCs remains under investigation, with evidence suggesting both a vascular origin and genetic abnormalities involving the USP6 gene. Diagnosis requires a multi-modal approach combining clinical assessment, imaging, and histology. Management strategies for ABCs range from surgical curettage and en bloc resection to minimally invasive techniques such as percutaneous sclerotherapy. Adjuvant therapies, including bone cement and Denosumab, are employed to reduce recurrence. In cases involving pathological fractures or neurological impairment, surgical intervention is often necessary. Despite these advances, recurrence remains a concern, particularly in spinal lesions. This case study discusses a 56-year-old male with a T11 pathological fracture secondary to a spinal ABC. He underwent neural decompression, debulking, and posterior spinal fusion, achieving favourable outcomes. The case highlights the challenges of treating ABCs, the importance of early diagnosis, and the role of multi-disciplinary management in preventing recurrence and ensuring long-term stability.