Abstract: BACKGROUND: Hollow screw treatment of femoral neck fractures is a common standard clinical operation. Combined with three-dimensional (3D) printing for surgical operations, the most typical one of the individualized surgical tools is the surgical guide plate. The guide plate not only can reduce the risk of screw penetration and cortical fracture, but also the screw placement is more accurate and efficient than traditional methods.  
OBJECTIVE: To explore the short-term clinical effects of hollow screws in the treatment of non-displaced femoral neck fractures with the assistance of 3D printed guide plates.
METHODS:  A retrospective analysis of 60 patients diagnosed with non-displaced femoral neck fractures in Qingdao Chengyang People’s Hospital of Shandong First Medical University from October 2016 to October 2019 was conducted. The surgical methods were all treated with hollow screw internal fixation. The patients were divided into study group and control group according to whether 3D printing was used or not (n=30 per group). The study group received 3D printed guide plates to assist screw placement, and the control group received traditional guides or freehand screw placement. The postoperative follow-up was 12 months. The operation time, the number of intraoperative fluoroscopy, the Harris score, the screw placement rate, and the distance between the three hollow screws and the femoral neck cortex were compared between the two groups.  
RESULTS AND CONCLUSION: (1) All the enrolled cases were followed up effectively, and the operation was successfully completed without complications, such as vascular and nerve injury. (2) The operation time of the study group was significantly shorter than that of the control group. The number of intraoperative fluoroscopy and the shortest distance of the hollow screw talar cortex of study group were better than those of the control group. There was a significant difference between the two groups (P < 0.05). (3) The occupancy rates of screw placement of the study group were better than those of the control group, but the difference between the groups was not statistically significant (P > 0.05). (4) The difference in Harris scores at the last follow-up between the two groups was not statistically significant (P > 0.05). (5) The results show that the 3D printed guide plate assisted hollow screws for the treatment of non-displaced femoral neck fractures can save operation time, reduce the number of intraoperative fluoroscopy, reduce blood loss, and optimize the spatial distribution of hollow screws while achieving good surgical results. Preventing the screws from returning and improving the fixing strength, the short-term clinical effect is obvious.

Key words: femoral neck fracture, non-displaced, hollow screw, 3D printing, guide plate