Aneurysmal Bone Cysts: Treatment with Direct PercutaneousEthibloc Injection. Long-Term Results

Purpose: To assess the efficacy and long-term results of Ethibloc treatment in aneurysmal bone cysts (ABC). Methods: Thirteen patients with ABC were treated with direct percutaneous Ethibloc injection. Four patients had only one injection and the other nine patients from two to four injections. No severe complications were observed; in two patients a local leakage of Ethibloc from the cyst into the soft tissues occurred but it was temporary and the consequent inflammation self-healed without residua and sequelae. Imaging follow-up lasted from 6 to 67 months and included conventional radiology (CR) and magnetic resonance imaging (MRI), both used in the presurgical phase. Results and Conclusions: All images demonstrated a remarkable shrinkage of the cystic lesion and bone cortex thickening. In all patients, circumscribed areas of lucency persisted at radiography, corresponding to residual cystic areas without fluid–fluid levels at MRI. Pain, which was present in all the patients before treatment, was relieved within a month. According to our experience, direct percutaneous Ethibloc injection is effective in the treatment of ABC and can be recommended as the first-choice treatment. Due to its higher sensitivity MRI must be included either in the pretreatment phase to study the multilocular structure or in the imaging follow-up to evaluate the efficacy of Ethibloc in persistently non-responsive areas.