Aggressive aneurysmal bone cysts. Endoscopic high-speed curettage combined with percutaneous bone grafting. Case Report

Abstract An aneurysmal bone cyst (ABC) is a benign, locally destructive hemorrhagic lesion, usually eccentrically located in the metaphysis of the long bones. A variety of treatments are available for the aggressive forms of aneurysmal bone cysts, ranging from curettage to en bloc resection technique in which the bone defect is reconstructed with vascularized or nonvascularized fibular autograft or allograft. We report a case of a 12-year-old boy with an aggressive ABC of the proximal humerus. This aggressive form of ABC had penetrated the proximal growth plate of the humerus and had expanded to the humeral epiphysis, up to the subchondral bone of the humeral head. He had been treated surgically, with an aggressive, high-speed endoscopic curettage and bone grafting of the cyst. To assess the functional recovery of the patient, the Modified Musculoskeletal Tumor Society Score was used. Successful healing of the ABC of the proximal humerus was evident four months postoperatively. The Modified Musculoskeletal Tumor Society Score was increased from 21 points preoperatively to 30 points, five years postoperatively. Endoscopic high-speed curettage allows a precise, thorough, and aggressive resection of the pathological tissue, which is essential for the successful healing of an aggressive ABC.