LAUSR

Introduction Osteosarcoma epidemiology in children younger than 5-year-old is very rare. Currently, limb salvage surgery becomes the preferred treatment in osteosarcoma. Wide excision using cryosurgery has been reported as an effective and safe procedure for malignant bone tumors. Case report A 5-year-old girl was presented with pain and a lump on her right knee. Physical examination showed a solid circumferential mass in the proximal tibia, with limited range of motion due to mass and pain. Osteoblastic lesion with a discrete margin and narrow transition zone on the proximal tibia from plain radiograph and magnetic resonance imaging (MRI) examination. Histopathological examination suggested osteosarcoma with a giant cell rich osteosarcoma subtype. Three cycles of neoadjuvant chemotherapy was conducted with cisplatin, ifosfamide, and adriamycin. We performed limb salvage surgery by wide excision with cryosurgery and vascularized fibular graft reconstruction. Wide excision was performed with the respect to preserve the epiphyseal plate. The proximal tibia segment was recycled using liquid nitrogen and re-implanted, fixed with a locking 2.7 mm T-plate and a straight reconstruction 2.7 mm reconstruction plate. Vascularized fibular graft was used to fill the bone defect on the medial side. Post-operative radiograph showed the plate and screws are well-fixated and the post-operative histopathological examination confirmed the diagnosis of conventional osteosarcoma HUVOS I. There was no post-operative complication observed, and the functional outcome was good. Conclusions Cryosurgery and vascularized fibular graft is a viable reconstructive option for proximal tibia osteosarcoma in very young children.