Aneurysmal bone cyst: a review of 150 patients.

We have reviewed a series of 150 aneurysmal bone cysts treated over the last 20 years. The lesions were principally located in the tibia, femur, pelvis, humerus, and spine and, in most cases, presented the imaging appearance originally described by Jaffe and Lichtenstein as a blowout with thin cortices. Only one of the patients was believed to have an osteoblastoma of the spine with secondary development of an aneurysmal bone cyst, and none of the patients developed additional lesions. The patients were treated primarily with curettage and implantation of allograft chips or polymethylmethacrylate, but some patients were treated with insertion of autografts or allografts. The local recurrence rate was 20%, which is consistent with that reported by other centers. Aneurysmal bone cysts are enigmatic lesions of unknown cause and presentation and are difficult to distinguish from other lesions. Overall, the treatment is satisfactory, but it is possible that newer approaches, such as improved magnetic resonance imaging studies, may help diagnose the lesions and allow the physicians to plan for more effective treatment protocols.