Reconstruction with 3D-printed modular pelvic endoprostheses after pelvic tumor resection

Abstract

Objective To investigate the ideal reconstruction methods after pelvic tumor resection and to assess the feasibility of three-dimensional (3D) printing technology for pelvic reconstruction, we performed a retrospective study of patients with pelvic tumors who received tumor resection and reconstruction using 3D-printed pelvic endoprostheses. Methods Thirty-five patients received tumor resection and functional reconstruction with 3D-printed pelvic endoprostheses in our center from Sep. 2013 to Dec. 2015. According to Enneking’s classification, there were 3 cases of Type I, 12 cases of Type II+III, 5 cases of Type I+II, 2 case of Type I+II+III, 10 cases of type I+II+IV and 3 cases of type I+II+III+IV resection. Methods of reconstruction included 3 patients with 3D-printed iliac endoprosthesis, 12 patients with 3D-printed standard hemipelvic endoprosthesis and 20 patients with 3D-printed screw-rod connected hemipelvic endoprosthesis. Results All 35 patients underwent en bloc resection. Margins were wide in 15 cases, marginal in 14 cases and intralesional in 6 cases. After a mean followed-up of 20.5 months (6 to 30), 25 patients survived without evidence of disease, 5 patients were alive with diseases and 5 patients died of distant metastasis. Complications included 7 cases of delayed wound healing, 2 cases of hip dislocation and no cases of deep infection. The average MSTS 93 score was 19.1 (9-26) for all of the 30 alive patients, 22.7 (20 to 25) for 3 patients with iliac endoprosthesis reconstruction, 19.8 (15 to 26) for 12 patients with standard hemipelvic endoprosthesis reconstruction, and 17.7 (9 to 25) for 15 patients with screw-rod connected hemipelvic endoprosthesis at the last follow up. Conclusion The application of 3D-printing technology could facilitate precise matching and osseointegration between the implants and host bone. Our clinical results proved that application of 3D-printed pelvic endoprostheses for reconstruction of bony defect was safe without additional complications, and that good functional results could be expected during short-term follow-up. Key words: Pelvis; Neoplasms; Prosthesis implantation; Computer-aided design