[Research on three-dimensional printing technology based on three-dimensional multimodality imaging to assist the operation of malignant bone tumors of limbs].

Objective: To explore the role and effectiveness of three-dimensional (3D) printing technology based on 3D multimodality imaging in surgical treatment of malignant bone tumors of limbs. Methods: The clinical data of 15 patients with malignant bone tumors of the limbs who met the selection criteria between January 2016 and January 2019 were retrospectively analyzed. There were 6 males and 9 females, with a median age of 34 years (range, 17-73 years). There were 5 cases of osteosarcoma, 3 cases of chondrosarcoma, 2 cases of Ewing sarcoma, 1 case of hemangiosarcoma, 1 case of ameloblastoma, and 3 cases of metastatic carcinoma. The tumors were located in the humerus in 5 cases, ulna in 2 cases, femur in 3 cases, and tibia in 5 cases. The disease duration was 2-8 months (median, 4 months). Preoperative 3D multimodality imaging was administered first, based on which computer-assisted preoperative planning was performed, 3D printed personalized special instruments and prostheses were designed, and Results: All 15 patients completed the operation according to the preoperative plan, and the surgical margins were all obtained wide resection margins. The operation time was 80-240 minutes, with a median of 150 minutes. The intraoperative blood loss was 100-400 mL, with a median of 200 mL. There was no significant limitation of limb function due to important blood vessels or nerves injury during operation. One case of superficial infection of the incision was cured after dressing change, and the incisions of the other patients healed by first intention. All patients were followed up 6-48 months, with a median of 24 months. Two of the patients died of lung metastasis at 6 and 24 months after operation, respectively. No local recurrence, prosthesis dislocation, or prosthesis loosening occurred during follow-up. At last follow-up, the MSTS score ranged from 23 to 30, with an average of 25. Conclusion: 3D printing tecnology, based on 3D multimodality imaging, facilitates precise resection and reconstruction for malignant bone tumors of limbs, resulting in improved oncological and functional outcome.