Development of a dual-trajectory guide plate using additive manufacturing for patients with osteoporosis

Pedicle screw fixation is a surgical procedure performed by clinically experienced physicians, and requires the precise placement of the screws in specific locations. The use of additive manufacturing in surgical procedures has gradually increased in recent years. Advantages of this technique include reduced difficulty of surgery and burden on physicians. The spinal dual-trajectory technique (DT) is a newly developed screw placement technology that is mainly used in patients with osteoporosis, and provides stable and strong spinal fixation to increase screw bonding strength. However, DT requires the placement of two screws oriented in different directions at the narrow pedicle, making the surgery more difficult and riskier than traditional pedicle fixation. This study integrates computer-aided design and additive manufacturing techniques to propose a complete design method for the DT guide plate. The developed guide plate was then installed in a three-dimensional vertebral model and the screw fixation process was implemented to verify the feasibility of the proposed method. The results show that the guide plate was able to implant screws in predefined directions without penetrating the structure of the vertebral body.