Purpose or Case Report: Aneurysmal bone cysts are benign expansile osseous lesions which may behave locally aggressively, leading to growth plate destruction, angular deformity, and pathologic fracture. Current treatments such as curettage and bone graft reconstruction, sclerosis, and intra-arterial embolization have high recurrence rates and morbidity. Percutaneous cryoablation is a promising new treatment modality. Three patients with ABCs underwent cryoablation at our institution and follow-up MRIs over the span of a year were obtained. This is the first study of its kind to elucidate the imaging findings post-cryoablation of ABCs, which may help the radiologist interpret response to treatment.
Methods & Materials: In this HIPAA compliant, IRB-approved study, three children with ABCs were treated using IcePearl percutaneous cryoablation needles (Galil Medical). Patients included an 11-year girl with a clavicular lesion, a 16 year-old girl with a femoral lesion, and a 14-year old boy with a femoral lesion. Clinical and imaging follow up with MRI occurred at 3, 6, and 12 months.
Results: Common imaging findings after cryoablation include resolution of fluid-fluid levels, decreased size of a T2-hyperintense core, appearance of a sclerotic rim of bone, and a cryoablation burn zone. All patients reported markedly decreased pain and return to normal activity by 6 months post treatment, including one patient able to play a full hockey game at 3 months. No major complications were reported. No clinical or imaging indicators were present to suggest recurrence.
Conclusions: ABCs are a difficult entity to treat with high recurrence rates and morbidity with current treatment options. After percutaneous cryoablation, ABCs may show common imaging findings which may help radiologists monitor treatment efficacy. All three patients treated at our institution showed excellent clinical results. Percutaneous cryoablation is a promising treatment modality for ABCs which in our series confers exceptional benefit to patient symptomatology without serious morbidity.