Clinical Application of a 3D-Printed Positioning Module and Navigation Template for Percutaneous Vertebroplasty

Background This study aimed to evaluate a personalized 3D-printed percutaneous vertebroplasty positioning module and navigation template based on preoperative CT scan data that was designed to treat patients with vertebral compression fractures caused by osteoporosis. Methods A total of 22 patients with vertebral compression fractures admitted to our hospital were included in the study. Positioning was performed with the new 3D-printed positioning module, and the navigation template was used for patients in the experimental group, and the traditional perspective method was used for patients in the control group. The experimental group consisted of 11 patients, 2 males and 9 females, with a mean age of 67.27 ± 11.86 years (range: 48 to 80 years), and the control group consisted of 11 patients, 3 males and 8 females, with a mean age of 74.27 ± 7.24 years (range: 63 to 89 years). The puncture positioning duration, number of intraoperative fluoroscopy sessions, and preoperative and postoperative visual analog scale (VAS) scores were statistically analyzed in both groups. Results The experimental group had shorter puncture positioning durations and fewer intraoperative fluoroscopy sessions than the control group, and the differences were statistically significant (P < .05). There were no significant differences in age or preoperative or postoperative VAS scores between the two groups (P > .05). Conclusions The new 3D-printed vertebroplasty positioning module and navigation template shortened the operation time and reduced the number of intraoperative fluoroscopy sessions. It also reduced the difficulty in performing percutaneous vertebroplasty and influenced the learning curve of senior doctors learning this operation to a certain degree.

Anatomic Study and Assembled Navigation Template-Assisted Implantation for Anterograde Transpubic Screws

Objective: Research the anatomical parameters of the anterograde transpubic screw corridor and evaluate the safety of anterograde transpubic screw placement assisted by the assembled navigation template.Methods: A total of 50 normal subjects, including 25 males and 25 females, underwent pelvic CT scanning in our hospital from January 2020 to September 2020. A 3D model of the ilium was established. The ilium was divided into zone Ⅰ, Ⅱ and Ⅲ according to Nakatani classification. The anterograde transpubic screw channel completely passes through zone Ⅰ and Ⅱ to form corridor A. The anterograde screw channel completely passes through zone Ⅰ, Ⅱ and Ⅲ to form corridor B. The diameter and length of the inner circle, the distance from the center of the inner circle to the posterior superior and to the inferior iliac spine of corridor A and corridor B were measured, respectively. A total of 9 patients underwent anterograde transpubic screw and transverse sacroiliac screw placement assisted by the assembled navigation template in our hospital, including 5 males and 4 females, were retrospectively analyzed. Operative time, blood loss, incision length and fluoroscopy times were recorded. Grading score and Matta score were evaluated after surgery.Results: In 50 normal subjects, the diameter of corridor A was 11.16±2.13 mm, and that of corridor B was 8.54±1.52mm, and the difference between the two corridors was statistically significant (P=0.000). The length of corridor A was 86.39±9.35 mm, and that of corridor B was 117.05±5.91 mm, with significant difference between the two corridors (P=0.000). The surface distance from the screw entry point to the posterior superior iliac spine in corridor A was 109.31± 11.06mm, and that in corridor B was 127.86± 8.23mm, the difference between the two corridors was statistically significant (P=0.000). The surface distance from the screw entry point to the posterior inferior iliac spine in corridor A was 91.16±10.34 mm, and that in corridor B was 106.92±7.91 mm. The difference between the two corridors was statistically significant (P=0.000). Nine patients successfully completed surgery, and a total of 18 sacroiliac transverse screws and 11 anterograde transpubic screws were inserted with the assistance of assembled navigation templates. The mean operation time of the 9 patients was 108.75±25.71 min, the blood loss was 141.11±50.21 ml, the incision length was 14±4.62 cm, and the intraoperative fluoroscopy was 17.89±4.01 times. Matta scores were excellent in 5 patients and good in 4 patients. One of the anterograde transpubic screw was in Grade 1, and 10 were in Grade 0. One S1 screw was in Grade 1, and 8 S1 screws were in Grade 0. Nine S2 screws were in Grade 0.Conclusions: Majority of the patients can accommodate anterograde transpubic screw s with diameter of 6.5 mm. Anterograde transpubic screw placement assisted by an assembled navigation template is clinically feasible, and with low cortical breaches.

Application of a Personalized Finite Element Analysis and 3D-Printed Navigation Template in The Treatment of Femoral Neck Fracture With Cannulated Screw

Purpose: To investigate the feasibility and accuracy of combining a personalized finite element analysis with 3D-printed navigation template on the treatment of femoral neck fracture (FNF) with cannulated screw. Methods: A total of 60 patients as unstable FNT with cannulated screw were evolved in this study from October 2016 to December 2019, who were randomly divided into two groups (n=30/group): The subjects in the study group were examined using the a finite element analysis according to the three-dimensional CT of hip joint before operation and then underwent 3D-printed navigation template of the femur to complete the implantation of the cannulated screw whereas the other 30 patients in the control group were underwent the implantation of the cannulated screw using the conventional FNF treatment in the inverted isosceles triangle. The success rate of one-time implantation of the cannulated screw, the postoperative shortest distance of talus cortex, and the healing of fracture, necrosis of femoral head and Harris function scores of hip joint in 12 months after operation were recorded and compared between the study and control groups.Results: According to the finite element analysis, the biomechanics of three screws were the most stable when they were close to the bone cortex (<3mm). Further more, it was demonstrated that the patients in the study group have more effectively success rate of one-time nail placement (93.33%) and significant reduction in the distance of talus cortex of cannulated screws (3.04 ± 0.39mm) than those in the control group (66.67% and 5.38±0.71mm). At 12 months post-surgery, higher healing rate of fracture (93.33%) and Harris functional score of hip (93.67 ± 4.01), as well as lower necrosis rate of femoral head (6.67%) were underwent in the study group when compared with the control group (83.33%, 91.57±4.18 and 16.67%). Conclusion: The results of this study suggest that combined application of a personalized finite element analysis and 3D-printed navigation template in the treatment of femoral neck fracture with cannulated screw can not only improve the effective nail placement, but also make the screw more in line with the requirements of biomechanical stability to promote the fracture healing and reduce the risk of femoral head necrosis. So it is a digital orthopedic technology for clinical popularization.

Efficacy Evaluation of 3D Navigational Template for Salter Osteotomy of DDH in Children

Background. The aim of this study is to retrospectively evaluate the efficacy of 3D navigational template for Salter osteotomy of DDH in children. Methods. Thirty-two consecutive patients with DDH who underwent Salter osteotomy were evaluated between July 2014 and August 2017, and they were divided into the conventional group ( n = 16 ) and navigation template group ( n = 16 ) according to different surgical methods. The corrective acetabular degrees, radiation exposure, and operation time were compared between the two groups. Results. No nerve palsy or redislocation was reported in the navigation template group. Compared with the conventional group, the navigation template group had the advantages of more accurate acetabular degrees, less radiation exposure, and shorter operation time ( P < 0.05 ). Meanwhile, the navigation template group achieved a better surgical outcome than the conventional group (McKay, P = 0.0293 ; Severin, P = 0.0949 ). Conclusions. The 3D navigational template for Salter osteotomy of DDH is simple and effective, which could be an alternative approach to improve the Salter osteotomy accuracy and optimize the efficacy.