A femoral neck fracture is the third most common type of fracture in trauma orthopedics, and it accounts for approximately 41% of hip fractures and 3.6% of total fractures [
The femoral neck fracture often occurs in elderly patients with osteoporosis, mainly due to low-energy injury [
In recent years, computer-aided design and 3D printing technology have become more widely used in the medical field [
From February 2019 to February 2020, 40 patients with a femoral neck fracture were operated in our hospital, and they were divided into two groups according to their preferences. Patients were included in the study if they presented with a simple femoral neck fracture without neurovascular injury. They were treated with three cannulated compression screws. Forty patients with femoral neck fractures were included in the study. Twenty patients were treated with 3D-printed guide plate-assisted screw placement (guide plate group), and the remaining 20 were treated with freehand screw placement under a C-arm X-ray fluoroscopy instrument (control group). The guide plate group comprised 7 male and 13 female patients, and the control group comprised 9 male and 11 female patients. Additional information about the patients is provided in Table
Patient information.
Group | Number of cases | Gender (M/F) | Age (years/range) | Injury side (right/left) | Garden classification (I, II, III, IV) |
---|---|---|---|---|---|
3D guide plate group | 20 | M: 7 | R: 10 | 6 II, 10 III, 4 IV | |
Control group | 20 | M: 9 | R: 12 | 8 II, 10 III, 2 IV |
The anatomical data of the patients were obtained by computed tomography (CT) scanning, and 3D models of the upper femur were reconstructed on the screen using medical digital imaging and an E3D digital medical modeling and design system (
Before the operation, the 3D-printed guide plate underwent plasma sterilization. After the femoral neck fracture was reduced by traction, the guide plate was placed percutaneously on the matching area of the proximal femur. With an assistant keeping the fracture stable, the surgeon maintained the position and direction of the guide plate stably with one hand and inserted the guide needle at the designed depth with the other hand. C-arm X-ray fluoroscopy was used to confirm that the insertion direction and guide needle depth were correct. Three cannulated compression screws were then implanted along the guide needle, according to the preoperative design. The position and angle of the three cannulated compression screws were determined by C-arm X-ray fluoroscopy, and the results were compared with the preoperative plan. The patients were followed up every 3 months. All patients were followed up successfully.
Data were analyzed using Prism 7.0 statistical software (GraphPad, San Diego, CA, USA). Normally distributed data are expressed as the
First, we performed a CT scan of the femoral neck fracture to collect detailed data (Figures
Digital 3D model reconstruction and preoperative planning. (a–d) CT scanning, multiplanar measurements, and reconstruction were performed for femoral neck fractures. (e–h) Computer-aided design and 3D simulation of femoral neck fracture reconstruction. (i–l) Computer-aided design and 3D simulation of the use of a guide plate and the surgical process of inserting three cannulated compression screws.
The 3D-printed guide plate was consistent with the anatomical characteristics of each individual. Under the guidance of the navigation template, the percutaneous insertion of the guide needle and the intraoperative C-arm fluoroscopy results were consistent with the preoperative design (Figures
The accuracy of computer-aided design and 3D printing technology for guide plate production. (a–d) The surgical procedure of 3D-printed guide plate-assisted percutaneous needle insertion and cannulated screw placement. (e–h) C-arm X-ray fluoroscopy was used to observe the cannulated compression screw placement. (i–l) Immediate postoperative CT was performed to evaluate fracture reduction and the position of the three cannulated compression screws.
All 40 patients were successfully followed up. The average follow-up time was 8 (range, 6–12) months. No avascular necrosis of the femoral head, screw withdrawal, or fractures occurred during the follow-up period (Figures
Postoperative follow-up results. (a–f) In the guide plate group, CT images show fracture healing in the final follow-up assessment of a representative 52-year-old female patient. (g–i) The hip function of a representative 52-year-old female patient at the final follow-up assessment.
The femoral neck fracture is the third most common type of fracture in traumatology, and various treatment options are available for it [
Therefore, a safe and effective method is needed to ensure the accuracy and safety of screw placement. A computer navigation system was once considered to be an acceptable auxiliary screw placement technology. However, the system’s shortcomings, such as inconvenient operation, cumbersome registration, and high cost, prevented it from being widely used in clinical practice. With the development of digital medicine, 3D printing technology has become widely used in orthopedics. This technology allows the optimization of preoperative design and the realization of individualized and precise treatments. In addition, it has been reported that 3D-printed personalized guide plates are safe and feasible to use for the treatment of intertrochanteric fractures in adults and of hip diseases in children [
In this study, digital orthopedic technology and 3D printing technology were combined in the guide plate group. A 3D-printed guide plate was used to assist in cannulated compression screw fixation of femoral neck fractures. Before the procedure, 3D reconstruction of the fracture site was performed using relevant software, and the resulting model could be rotated and transparently processed to preview the screw placement and adjust the screw path to the optimal path. Therefore, the required length and diameter of the screw could be determined before the procedure. A 1 : 1 fracture model was also printed before the procedure. The navigation template of auxiliary screw placement allowed the surgeon to simulate the procedure on the model, operate skillfully, and evaluate the difficulties and results of the procedure. It is also expected to be helpful for beginners to master the necessary surgical process and skills.
The use of a 3D-printed guide plate to assist the placement of cannulated compression screws for the internal fixation of femoral neck fractures has many advantages. First, it greatly simplifies and optimizes intraoperative procedures. The time taken to complete the procedure was greatly reduced, and the multiple intraoperative fluoroscopies, screw path sounding, and screw selection steps were eliminated. Specifically, the time taken to complete the procedure and the number of intraoperative X-ray fluoroscopy images were significantly less in the guide plate group than in the control group. Second, this procedure is convenient for junior doctors to master, and thus, they are more likely to promote this type of surgery. During the procedure, the guide plate only needs to be placed in the predesigned position, and the screw can be accurately placed without the need for multiple perspectives. Third, the biggest characteristic in this study is the positional Kirschner wire in front of the femoral neck and the designed catheter matching on the surface of the lateral femoral, thus guaranteeing the use of the minimally invasive method and the accuracy of the method at the same time. Moreover, because this guide plate-assisted procedure has a short learning curve and is easy to master, it can be performed in relatively poorly equipped hospitals.
In conclusion, the use of computer-aided design and a 3D-printed navigation template improved the accuracy of cannulated compression screw implantation for the treatment of femoral neck fractures. It reduced the risk of iatrogenic injury to the femoral neck and vascular system and reduced implantation time, intraoperative bleeding, and X-ray exposure. With further improvements in efficiency and safety, this technology has the potential to be widely adopted.
The data used to support the findings of this study are available from the corresponding author upon request.
All authors declare no conflicts of interest.
This work was supported by the Key Project of Hunan Provincial Science and Technology Innovation (No. 2020SK1014-2).