128P Innovative limb salvage: Liquid nitrogen approach in reconstruction after bone tumor resection

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Various techniques for reconstructing bone and soft tissue defects after removing malignant bone tumors have been described. Typically, a tumor prosthesis is employed for reconstruction following osteosarcoma removal. However, the extended use of artificial materials poses durability challenges over time, leading to the necessity for many patients to undergo revisions due to prosthetic looseness or damage. Biological regeneration using tumor-bearing bone treated with liquid nitrogen helps overcome disadvantages and brings many outstanding advantages. From 2021 to 2023, 15 patients with bone tumor resection and reconstruction using liquid nitrogen treated autologous bone graft were recruited: 3 cases in the distal tibia, 3 cases in the middle tibia, 1 case in the proximal humerus, 2 case in the distal fibula, 2 case in the ulna and 4 cases in the distal femur. On the bone segment containing the tumor, we cut a portion of the bone that remains structurally sound. The resected bone was dipped in liquid nitrogen for 25 min, thawed at room temperature for 15 min followed by dipping in betadin-mixed saline for 10 min. Finally, the bone was fixed with intramedullary needles or plate for reconstruction. The reconstruction provides good local control and functional outcome. At a mean follow-up of 18 months, there were 1 patients with lung metastases after completing postoperative chemotherapy, there was no local recurrence, 1 patient had a surgical wound infection. Signs of bone union in the graft are typically detected within an average of 7 months and the average bone healing times were 12 months. The mean functional Musculoskeletal Tumor Society (MSTS) score was 80%. Autologous bone graft treated with liquid nitrogen is a viable option for reconstructing biologically deficient bone after tumor resection, especially in areas challenging to reconstruct using prothesis. It provides satisfactory outcomes with low rates of infection and local recurrence, contributing to cost savings.