Aneurysmal bone cyst of the spine treated by concentrated bone marrow: clinical cases and review of the literature

ABC is a benign lesion with unpredictable behavior. Its treatment is challenging, especially in poorly accessible surgical areas, such as spine and pelvis. Currently, the first-line treatment of ABC is repeated selective arterial embolization (SAE) until healing. Other options have been used with variable success rates. We propose an alternative treatment for spine aneurysmal bone cyst (sABC) based on the injection of concentrated autologous bone marrow. We retrospectively report and analyze here two cases of patients, a 14-year-old girl and a 16-year-old boy, both affected by ABC in C2 vertebra which were impossible to treat by SAE. They were treated with single or repeated injection of concentrated autologous bone marrow into the lesion. Their follow-up period is 27 months for both patients. In the two cases reported here we observed a progressive ossification of the lesion, which was slow in one case, requiring three subsequent injections of concentrated bone marrow, and fast in the other case, beginning 1 month after the procedure. In both cases, the healing of the lesion was associated with symptom relief and the clinical status of the patients remains stable after 2 years. Although SAE can still be considered the first line in the treatment of ABC in the axial skeleton, new promising therapeutic procedures involving the use of mesenchymal stem cells are developing.