Bone within bone appearance in a pathological fracture

A 60-year-old man presented to our hospital with complaints of pain and deformity on his right thigh for the past 2 days following a history of accidental slip and fall. Radiological investigations suggested a pathological type 2 Seinsheimer subtrochanteric fracture of the right femur with a 'bone within bone' appearance, which posed a diagnostic dilemma as this radiological appearance is seen in a spectrum of conditions. Radiographic skeletal survey failed to identify a similar appearance elsewhere in the body. Laboratory investigations pointed in favour of bone mineral disease, and histopathological examination of the bone narrowed it down to Paget's disease. The fracture was fixed with a contralateral distal femur locking compression plate. The fracture site failed to show signs of union until 6 months postsurgery and hence the patient was advised for grafting procedure. The patient deferred surgery and remains without major complications until 18 months of follow-up.