New Insight in Pediatric Orthopedic Oncology: The Use of a Xeno-Hybrid Bone Substitute in Loss of Bone Tissue After Oncological Resections, a Case Series

<b>Background</b>: The management of bone defects in pediatric oncology represents a major challenge in orthopedics, as it requires preserving both joint function and skeletal growth. Traditional reconstructive approaches, such as autografts and allografts, are limited by availability, complications, and incomplete biological integration. In this context, xeno-hybrid bone substitutes have emerged as a promising alternative. The aim of this study was to evaluate the safety and effectiveness of SmartBone^® ORTHO in the reconstruction of post-oncological bone defects in children. <b>Methods:</b> Twelve pediatric patients treated at the Centro Traumatologico Ortopedico (CTO) and OIRM Hospital, AOU Città della Salute e della Scienza of Turin (Italy), between 2016 and 2019 were retrospectively analyzed. Lesions included simple and aneurysmal bone cysts, non-ossifying fibroma, chondroblastoma, and other benign conditions. All patients underwent curettage followed by defect filling with SmartBone^® ORTHO. <b>Results:</b> At clinical and radiological follow-up, nine patients (75%) showed stable graft integration and complete functional recovery. Three patients (25%) developed local recurrence, which was managed with revision surgery and re-implantation of SmartBone^®, with all achieving stable outcomes. Radiographs demonstrated progressive increases in bone density and trabecular thickness, reaching values comparable to those of native bone within 6-12 months. <b>Conclusions</b>: SmartBone^® ORTHO proved to be a safe and effective biomaterial for pediatric post-oncological bone reconstruction, promoting rapid osteointegration and physiological bone remodeling without infection or intolerance.