Abstract: BACKGROUND: Compared with traditional pedicle screws, cortical bone trajectory screw provides a more secure fixation by running entirely through cortical bone. However, precise and safe implantation of cortical bone trajectory screws requires high technical expertise from spine surgeons. Theoretically, the use of personalized guides produced with 3D printing technology can potentially enhance accuracy, streamline the procedure, and enhance surgical efficiency, but there is limited scholarly literature available on this topic.
OBJECTIVE: To investigate the accuracy and safety of utilizing personalized 3D printed guide plates to assist in the placement of cortical bone trajectory screws in thoracolumbar fractures complicated with osteoporosis.
METHODS: A total of 58 patients with thoracolumbar spine fractures (T11-L4) complicated with osteoporosis who underwent internal fixation using cortical bone trajectory screws between January 2020 and January 2024 were selected for this study. In total, 348 screws were analyzed, and the patients were divided into two groups based on the surgical approach. The 3D guide group consisted of 30 patients who received personalized 3D printing-assisted screw placement, accounting for 180 screws. The control group comprised 28 patients, in which a total of 168 screws were placed manually. The effectiveness and applicability of the different surgical methods were evaluated by comparing operative indicators, the accuracy of screw placement, the reduction of injured vertebrae, the correction of kyphotic deformity, and postoperative outcomes between the two groups.
RESULTS AND CONCLUSION: (1) The 3D guide group demonstrated significant improvements over the control group across several operation-related metrics, including incision length, operation time, screw placement time, fluoroscopy times, intraoperative blood loss, postoperative drainage volume, and length of hospitalization (P < 0.05). However, there was no significant difference in the total cost between the two groups (P > 0.05). (2) The accuracy of screw placement was higher in the 3D guide group, with a significantly lower invasion rate of screws to the upper articular process compared with the control group (P < 0.05). (3) Postoperative evaluations revealed that the anterior vertebral height, Cobb angle, visual analog scale score, and Oswestry disability index improved for both groups relative to pre-surgery measurements, with these differences being statistically significant (P < 0.05). Compared with the other groups, the 3D guide group had a lower Oswestry disability index, indicating superior thoracolumbar function (P < 0.05). However, no significant differences were observed between the groups regarding postoperative anterior vertebral height, Cobb angle, and visual analog scale scores (P > 0.05). (4) Throughout the perioperative and follow-up periods, no complications were reported in either group. (5) It is indicated that the use of a personalized 3D printed guide plate for assisting in the placement of cortical bone trajectory screws in the treatment of thoracolumbar fractures with osteoporosis is feasible approach, offering advantages such as minimal invasiveness, efficiency, accuracy, safety, and satisfactory clinical outcomes.

Key words: thoracolumbar vertebral fractures, osteoporosis, cortical bone trajectory screw, internal fixation, 3D printed guide plate, screw placement accuracy