Giant aneurysmal bone cyst in the distal tibia, treated with tibialization of the fibula (Tully technique) and bone substitutes.

Abstract

Introduction: Bone cysts (BCs) are benign lesions formed by fluid-filled cavities that tend to expand and weaken the bone locally. In most cases, they originate in the metaphyses of long bones adjacent to the physis. Then, with bone growth, they tend to move away from the physis, making an apparent migration towards the diaphyseal-metaphyseal region or even towards the diaphysis. They affect growing patients, up to 85% of whom are under 20 years of age, and the most affected age group is the segment between 10 and 20 years.

Clinical case: 9-year-old girl with difficulty walking. She was diagnosed in a rural hospital with a closed fracture of the left tibia and treated with immobilization for 1 month. In the control x-ray, a radio-opaque image with a fluid level in the lower epiphysis of the left tibia is observed.

Evolution: She underwent a five-stage surgery: 1) a block of +/- 4 x 5 cm of autologous cortico-cancellous bone graft was obtained. 2) External fixation, with the placement of a monoplane external tutor. 3) Ostectomy of +/- 7 cm length of the left fibula. 4) Radical resection of the cyst structure. 5) Placement of the autograft using the Tully technique.