Single-Stage Combined Embolization and Structural Allograft Reconstruction for Proximal Humerus Aneurysmal Bone Cysts in Children

Background: Aneurysmal bone cysts (ABCs) of the proximal humerus in children are rare, locally aggressive lesions associated with substantial recurrence rates and risk of structural instability. Conventional treatment by curettage and bone grafting is often limited by recurrence, while selective arterial embolization (SAE) alone may not provide sufficient structural support. This study evaluates a single-stage treatment strategy combining embolization and structural reconstruction to address both the vascular and mechanical components of the disease. Methods: A retrospective analysis was performed on 12 pediatric patients (median age 9 years) with proximal humerus ABCs treated between 2020 and 2024. All patients underwent a standardized single-stage protocol consisting of preoperative SAE, intralesional resection with high-speed burr, and reconstruction using an allogeneic fibula graft combined with cancellous bone augmentation. Radiological consolidation, recurrence, and functional outcomes were assessed. Associations between prior surgery, cyst size, and recurrence were analyzed. Results: Primary consolidation was achieved in 75% of patients, with an overall healing rate of 91.7% after secondary interventions. Recurrence occurred in 16.7% of cases and was significantly associated with prior surgical treatment (p = 0.045). No significant correlation was found between cyst size and recurrence (p = 0.151). At final follow-up (median 8.5 months), all patients demonstrated complete healing according to the modified Neer classification following completion of treatment. Functional outcomes were favorable, with 91.7% of patients regaining full range of motion and no neurovascular complications observed. Conclusions: The presented single-stage approach combining SAE, intralesional resection, and structural allograft reconstruction addresses both the vascular supply and mechanical instability of proximal humerus ABCs. This strategy demonstrated high healing rates and favorable functional outcomes, with acceptable recurrence rates in this cohort while avoiding donor site morbidity. It represents a practical and effective treatment concept for this rare pediatric condition.