Clinical application of new three-dimensional honeycomb guide in percutaneous cannulated screw fixation of femoral neck fracture

Abstract

To design a new type of three-dimensional honeycomb guide for percutaneous cannulated screw placement in femoral neck fracture and evaluate its effectiveness. The clinical data of 40 patients with femoral neck fracture who met the selection criteria between June 2019 and December 2020 were retrospectively analyzed. According to different intraoperative positioning methods, they were divided into control group (20 cases, free hand positioning screws) and study group (20 cases, new guide assisted positioning screws). There was no significant difference in gender, age, side, cause of injury, Garden classification, and time from injury to operation between the two groups ( P>0.05). The operation time, fluoroscopy times, guide needle puncture times, and fracture healing time of the two groups were recorded. The hip function was evaluated by Harris score at last follow-up. At immediate after operation, the following imaging indexes were used to evaluate the accuracy of screw implantation distribution: screw spacing, screw coverage area, distance from screw to cervical cortex, parallelism between screws, and screw to cervical axial deviation. All operations were successfully completed, and the guide needle did not penetrate the femoral neck cortex. There was no significant difference in operation time and fluoroscopy times between the two groups ( P>0.05); the guide needle puncture times in the study group was significantly less than that in the control group ( t=8.209, P=0.000). Imaging detection at immediate after operation showed that the screw spacing and screw coverage area in the study group were significantly greater than those in the control group ( P<0.05); the distance from screw to cervical cortex, parallelism between screws, and screw to cervical axial deviation were significantly smaller than those in the control group ( P<0.05). All patients were followed up 7-25 months, with an average of 19.3 months. There was no significant difference in follow-up time between the two groups ( t=-0.349, P=0.729). There were 2 cases of fracture nonunion in the control group and 1 case in the study group, and the other fractures completely healed. One case of osteonecrosis of the femoral head occurred in the control group. During the follow-up, there was no complication such as vascular and nerve injury, venous thrombosis, screw penetration, withdrawal, breakage, and refracture, etc. There was no significant difference in fracture healing time and Harris score at last follow-up between the two groups ( P>0.05). The new three-dimensional honeycomb guide has the advantages of simple structure and convenient use. It can reduce the puncture times of the guide needle and effectively improve the accuracy distribution of cannulated screw implantation.