Reconstruction of Tumor-Induced Pelvic Defects With Customized, Three-Dimensional Printed Prostheses

Abstract

Background: Reconstruction of pelvis girdle stability after tumor-induced hemipelvectomy remains challenging. We surgically treated 13 patients with custom-made, three-dimensional printed hemipelvic prostheses. We aim to identify the preliminary outcomes for patients who have been managed with more mixed regions of prosthetic pelvic reconstruction and the feasibility of two reconstructive systems.

Methods: Seven male patients and 6 female patients treated at our center between January 2019 and May 2021 were included. There were 11 primary sarcomas and 2 solitary bone metastases. After en bloc tumor resection, two types of personalized, three-dimensional printed prostheses were fixed to restore the stability and rebuild the load transfer. The position of the reconstructed hemipelvis was evaluated on an anteroposterior plain radiograph. The complications and outcomes were traced. One amputation specimen was discovered through histological analysis of the porous structure.

Results: The operative duration was 467 ± 144 min, and the blood loss was 3,119 ± 662 ml. During a follow-up of 22.4 ± 8.5 months, two patients had delayed wound healing and one had a second-stage flap transfer. One patient with osteosarcoma died of pulmonary metastasis 27 months after surgery. Two patients with marginal resection suffered from local recurrence and had extra surgeries. One patient had traumatic hip dislocation 2 months after surgery and manipulative reduction was performed. The acetabular inclination of the affected side was 42.2 ± 4.3°, compared with 42.1 ± 3.9° on the contralateral side. The horizontal distance between the center of the femoral head and the middle vertical line was 10.4 ± 0.6 cm, while the reconstructed side was 9.8 ± 0.8 cm. No significant difference in acetabular position after surgery was found (p > 0.05). The amputation specimen harvested from one patient with local recurrence demonstrated bone and soft tissue ingrowth within the three-dimensional printed trabecular structure. Walking ability was preserved in all patients who are still alive and no prosthesis-related complications occurred. The MSTS score was 22.0 ± 3.7.

Conclusions: Both types of custom-made, three-dimensional printed prostheses manifested excellent precision, mechanical stability, and promising functional rehabilitation. The porous structure exhibited favorable histocompatibility to facilitate the ingrowth of bone and soft tissue.

Keywords: 3D printing; endoprosthesis; hemipelvic reconstruction; pelvic tumor; porous.

Figure 1

A 53-year-old female patient with chondrosarcoma. (A) Preoperative MRI showed the invasion of the sacroiliac joint. (B) The design of Type A prosthesis (green part: porous structure; blue part: solid structure). (C) The 3D-printed prosthesis with lattice bone contact surface. (D) Intraoperative installation of patient-specific drill guide at the auricular surface. (E) Installation of 3D-printed prosthesis. (F) Immediate x-ray after surgery showed that the prosthesis was fitted precisely.

Figure 2

A 66-year-old male patient with metastatic prostate cancer. (A) The design of type B prosthesis after partial type I + II + III resection (green part: porous structure; blue part: solid structure). (B) The real picture of the implant. (C) Intraoperative installation of patient-specific osteotomy guide on the iliac crest. (D) Extra-articular resection of the tumor. (E) Postoperative x-ray manifested promising accuracy of the prosthesis.

Figure 3

A 52-year-old female patient with recurrent chondrosarcoma 11 months after prosthetic implantation. (A) Type B prosthesis after type II + III resection. (B) Postoperative x-ray showed excellent shape compatibility. (C) The gross specimen of the affected hemipelvis. (D) The cross section showed the osseointegration ability of the porous structure. (E) Fibrous tissue could extend to the 3D-printed macro pores.