Biomechanical analysis and clinical application of 3D printed bone tumor prosthesis of lower limb / 中华骨科杂志

ABSTRACT

Objective:To design 3D printed prosthesis in an individualized way and explore the short-term clinical efficacy of reconstruction of segmental defect after resection of bone tumor in lower extremities with 3D-printed prosthesis.Methods:From January 2017 to June 2019, 6 patients with lower limb bone tumor who met the inclusion criteria were recruited, including 3 males and 3 females, aged 8.67±1.11 years (range 6-11 years). All 6 cases were primary bone tumors, and the Enneking stages were all IIB, including 3 cases of left tibial tumors, 2 cases of right tibial tumors, and 1 case of right femoral tumor. These 3D-printed prostheses were designed based on the preoperative imaging data. The mechanical stability of the prosthesis was evaluated by three-dimensional finite element analysis. After tumor resection, the 3D-printed prosthesis was installed and fixed to reconstruct the segmental bone defect. All patients were clinically followed up and evaluated by imaging regularly after operation. The functional status was assessed by the Musculoskeletal Tumor Society (MSTS) score. Oncology results and complications were recorded in detail.Results:All operations were successfully performed, including 3 cases underwent left tibial tumor resection, 2 cases underwent right tibial tumor resection, and 1 case underwent right femoral tumor resection. The length of the bone defect after tumor resection was 18.19±3.74 cm, the average operation time was 165.83±54.17 min, and the average intraoperative bleeding was 233.33±133.33 ml. These finite element analysis data show that the overall stress of these prostheses are lower than the maximum mechanical strength of the corresponding materials. These 3D printed prostheses match well with the excision defect and meet the expected effect. There were no adverse reactions during the operation. The mean follow-up period was 16.83±7.17 months. At the last follow-up, all patients survived without tumor recurrence or metastasis. Postoperative imaging results showed that all the implants were stable without complications such as peripheral infection, aseptic loosening, prosthesis fracture. These 3D-printed prostheses composite resulted in substantial bone integration at follow-up. The average MSTS score was 83.67%±9.11%.Conclusion:The individualized 3D printed prosthesis can be used to reconstruct the bone defect after the resection of osteosarcoma in the lower extremities, and the clinical efficacy was satisfactory in the short-term follow-up.