ABSTRACT
Objective To explore the feasibility and clinical efficacy of long-segmental bone defects after en bloc tumor resection of lower limb segment with composite of titanium alloy 3D printed prosthesis and vascularized fibular autograft and bioceramics.Methods 5 patients with lower extremity tumor (1 high grade chondrosarcoma,1 Ewing sarcoma,1 single metastatic tumor and 2 osteosarcoma) were treated by en bloc resection and precise reconstruction with segmental 3D-printed,custom-made prosthesis from August 2015 to November 2016,which composed of 1 male and 4 females,ranged from 16 to 56 years old,the average was 32± 19.3 years old.Three-dimensional computed tomography reconstructed images of patients' tumors were built before surgery.Custom-made prostheses were manufactured based on the patients' reconstructed images with micro-pores on the surface.After en bloc tumor resection with the help of osteotomy guide plate,the defects were reconstructed with 3D-printed,custom-made prostheses.Vascularized fibular autografts were put inside the prostheses,and the interval space among them was filled with bioceramics.Results All the 5 cases were performed surgical planning before the surgery with prosthesis and guide plate were designed at the same time.After verification of the finite element analysis SLM (2 cases) and the EBM (3 cases) were used to process prosthesis,and were designed into porous sharp with 210.98±66.16 mm in length and 26 901.76±12 903.96 mm3 in volume.Then the prosthesis would be cleaned and sterilized.All 5 operation were proceeded according to the plan of preoperative.The intra-operative guide plate were installed on the bone surface stably.The bone cutting was guided according to the plan of preoperative.By intra-operative frozen pathological examination,there were no malignant tissues in near and far marrow cavity.Unfolded fibular flap with 168.75±49.07 mm in length and porous tricalcium phosphate particle composite implants with 10±4.08 g were used in 4 cases and bone cement was used in 1 cases of metastatic tumor.The average operation time was 261±85 min and average blood loss was 540±182 ml.After a mean follow-up time of 6.4 months (1-15 months),all 5 cases survived with no local recurrence and pulmonary metastasis tumor.2 cases with vascular pedicle fibular transplant confirmed the survival of fibula via bone scan 3 months after operation.All cases were no infection,fractures,prosthesis loosening,except broken screw in 1 case.The Musculoskeletal Tumor Society (MSTS) 93 score was 17-26.Conclusion Long segment tubular titanium alloy 3D printed prosthesis with vascularized fibular autograft and bioceramics could reconstruct the segmental defects caused by tumor resection.