Objective:To evaluate our self-designed novel guide device for cannulated screwing in the treatment of femoral neck fracture.Methods:Between June 2019 and July 2020, 40 patients with femoral neck fracture were treated with cannulated screwing at Department of Orthopaedics, The Second Hospital Affiliated to Shanxi Medical University. They were divided into a manual group of 20 cases whose cannulated screwing was implemented by hand and a guide group of 20 cases whose cannulated screwing was implemented with the aid of our self-designed guide device. In the guide group, there were 5 males and 15 females, with an age of (48.4±10.2) years (from 18 to 63 years); there were 12 cases of types Ⅰ & Ⅱ and 8 cases of types Ⅲ & Ⅳ by the Garden classification. In the manual group, there were 8 males and 12 females, with an age of (49.8±8.4) years (from 18 to 60 years); there were 13 cases of types Ⅰ & Ⅱ and 7 cases of types Ⅲ & Ⅳ by the Garden classification. All fractures underwent closed reduction and internal fixation with 3 cannulated screws. The intraoperative fluoroscopy, operation time, femoral cortex drilling, angle between the guide pin and the femoral neck axis in the anteroposterior view, angle between the guide pin and the femoral neck axis in the lateral view, fracture healing time, Harris hip score and complications were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). In the guide group, intraoperative fluoroscopy [(10.0±2.2) times], operation time [(41.8±5.6) min], femoral cortex drilling [(4.5±1.1) times], angle between the guide pin and the femoral neck axis in the anteroposterior view (3.0°±0.8°) angle between the guide pin and the femoral neck axis in the lateral view (3.9°±1.0°) and fracture healing time [(6.2±0.5) months] were significantly less or smaller than those in the manual group [(24.8±8.3) times, (60.0±15.3) min, (12.8±2.0) times, 7.2°±1.8°, 7.6°±2.6°, and (7.2±0.5) months] (all P<0.05). There was no significant difference in Harris hip score between the 2 groups ( P>0.05). None of the patients had wound infection, internal fixation displacement, fracture nonunion or screw breakage. Conclusions:Application of our self-designed guide device can shorten operation time, improve accuracy of needle insertion, and reduce drilling attempts in the femoral cortex, making cannulated screwing easier for femoral neck fractures.