OBJECTIVE: To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures. METHODS: A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups ( P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up. RESULTS: All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences ( P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction ( P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups ( P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups ( P>0.05). CONCLUSION Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.
Humans ; Fracture Fixation, Internal/methods* ; Retrospective Studies ; Imaging, Three-Dimensional ; Bone Screws ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; Spinal Fractures/surgery* ; Fractures, Bone/surgery* ; Pelvic Bones/injuries* ; Postoperative Complications ; Neck Injuries

The registration of preoperative magnetic resonance (MR) images and intraoperative ultrasound (US) images is very important in the planning of brain tumor surgery and during surgery. Considering that the two-modality images have different intensity range and resolution, and the US images are degraded by lots of speckle noises, a self-similarity context (SSC) descriptor based on local neighborhood information was adopted to define the similarity measure. The ultrasound images were considered as the reference, the corners were extracted as the key points using three-dimensional differential operators, and the dense displacement sampling discrete optimization algorithm was adopted for registration. The whole registration process was divided into two stages including the affine registration and the elastic registration. In the affine registration stage, the image was decomposed using multi-resolution scheme, and in the elastic registration stage, the displacement vectors of key points were regularized using the minimum convolution and mean field reasoning strategies. The registration experiment was performed on the preoperative MR images and intraoperative US images of 22 patients. The overall error after affine registration was (1.57 ± 0.30) mm, and the average computation time of each pair of images was only 1.36 s; while the overall error after elastic registration was further reduced to (1.40 ± 0.28) mm, and the average registration time was 1.53 s. The experimental results show that the proposed method has prominent registration accuracy and high computational efficiency.
Humans ; Imaging, Three-Dimensional/methods* ; Magnetic Resonance Imaging/methods* ; Ultrasonography/methods* ; Algorithms ; Surgery, Computer-Assisted/methods*

OBJECTIVE: To explore the effectiveness of a new point contact pedicle navigation template (referred to as "new navigation template" for simplicity) in assisting screw implantation in scoliosis correction surgery. METHODS: Twenty-five patients with scoliosis, who met the selection criteria between February 2020 and February 2023, were selected as the trial group. During the scoliosis correction surgery, the three-dimensional printed new navigation template was used to assist in screw implantation. Fifty patients who had undergone screw implantation with traditional free-hand implantation technique between February 2019 and February 2023 were matched according to the inclusion and exclusion criteria as the control group. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, disease duration, Cobb angle on the coronal plane of the main curve, Cobb angle at the Bending position of the main curve, the position of the apical vertebrae of the main curve, and the number of vertebrae with the pedicle diameter lower than 50%/75% of the national average, and the number of patients whose apical vertebrae rotation exceeded 40°. The number of fused vertebrae, the number of pedicle screws, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were compared between the two groups. The occurrence of implant complications was observed. Based on the X-ray films at 2 weeks after operation, the pedicle screw grading was recorded, the accuracy of the implant and the main curvature correction rate were calculated. RESULTS: Both groups successfully completed the surgeries. Among them, the trial group implanted 267 screws and fused 177 vertebrae; the control group implanted 523 screws and fused 358 vertebrae. There was no significant difference between the two groups ( P>0.05) in terms of the number of fused vertebrae, the number of pedicle screws, the pedicle screw grading and accuracy, and the main curvature correction rate. However, the time of pedicle screw implantation, implant bleeding, fluoroscopy frequency, and manual diversion frequency were significantly lower in trial group than in control group ( P<0.05). There was no complications related to screws implantation during or after operation in the two groups. CONCLUSION The new navigation template is suitable for all kinds of deformed vertebral lamina and articular process, which not only improves the accuracy of screw implantation, but also reduces the difficulty of operation, shortens the operation time, and reduces intraoperative bleeding.
Humans ; Orthopedic Procedures ; Pedicle Screws ; Retrospective Studies ; Scoliosis/surgery* ; Spinal Fusion/methods* ; Spine ; Surgery, Computer-Assisted/methods*

Computer-assisted technology are gradually integrated into dental education and clinical treatment. As a cutting-edge technology in computer-aided medicine, augmented reality can not only be used as an aid to dental education by presenting three-dimensional scenes for teaching demonstration and experimental skills training, but also can superimpose virtual image information of patients onto real lesion areas for real-time feedback and intraoperative navigation. This review explores the current applications and limitations of augmented reality in dentistry to provide a reference for future research.
Humans ; Augmented Reality ; Oral Medicine ; Surgery, Computer-Assisted/methods* ; Imaging, Three-Dimensional

In the past decades,a dramatic development of navigation technology in orthopaedic surgery has been witnessed. By assisting the localization of surgical region,verification of target bony structure,preoperative planning of fixation,intraoperative identification of planned entry point and direction of instruments or even automated insertion of implants,its ability and potential to reduce operation time,intraoperative radiation,surgical trauma,and improve accuracy has been proved. However,in contrast to the widespread use of navigation technology in arthroplasty,orthopaedic tumor,and spine surgery,its application in orthopaedic trauma is relatively less. In this manuscript,the main purpose is to introduce the technical principles of navigation devices,outline the current clinical application of navigation systems in orthopaedic trauma,analyze the current challenges confronting its further application in clinical practice and its prospect in the future.
Humans ; Orthopedics ; Surgery, Computer-Assisted/methods* ; Orthopedic Procedures/methods* ; Operative Time

OBJECTIVE: To explore the feasibility and accuracy of ultrasound volume navigation (UVN) combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation through a prospective randomized controlled study. METHODS: Patients with thoracic and lumbar vertebral fractures scheduled for percutaneous pedicle screw fixation between January 2022 and January 2023 were enrolled. Among them, 60 patients met the selection criteria and were included in the study. There were 28 males and 32 females, with an average age of 49.5 years (range, 29-60 years). The cause of injury included 20 cases of traffic accidents, 21 cases of falls, 17 cases of slips, and 2 cases of heavy object impact. The interval from injury to hospital admission ranged from 1 to 5 days (mean, 1.57 days). The fracture located at T ₁₂ in 15 cases, L ₁ in 20 cases, L ₂ in 19 cases, and L ₃ in 6 cases. The study used each patient as their own control, randomly guiding pedicle screw implantation using UVN combined with X-ray fluoroscopy on one side of the vertebral body and the adjacent segment (trial group), while the other side was implanted under X-ray fluoroscopy (control group). A total of 4 screws and 2 rods were implanted in each patient. The implantation time and fluoroscopy frequency during implantation of each screw, angle deviation and distance deviation between actual and preoperative planned trajectory by imaging examination, and the occurrence of zygapophysial joint invasion were recorded. RESULTS: In terms of screw implantation time, fluoroscopy frequency, angle deviation, distance deviation, and incidence of zygapophysial joint invasion, the trial group showed superior results compared to the control group, and the differences were significant ( P<0.05). CONCLUSION UVN combined with X-ray fluoroscopy-guided percutaneous pedicle screw implantation can yreduce screw implantation time, adjust dynamically, reduce operational difficulty, and reduce radiation damage.
Male ; Female ; Humans ; Middle Aged ; Pedicle Screws ; Prospective Studies ; X-Rays ; Surgery, Computer-Assisted/methods* ; Spinal Fusion/methods* ; Fluoroscopy/methods* ; Lumbar Vertebrae/injuries*

The precision of optical positioning system is one of the most important factors which affects the precision of navigation guided surgery. In this study, an efficient and low-cost tool and its algorithm were proposed to evaluate the accuracy of optical positioning system based on the ablation scenario of liver cancer, and two validation experiments were designed. Experimental results show that the tool and its algorithm can evaluate the accuracy of the current positioning system accurately and efficiently.
Algorithms ; Humans ; Liver Neoplasms/surgery* ; Optical Devices ; Surgery, Computer-Assisted/methods*

The use of dynamic navigation technology in edentulous jaw implant restoration can solve many problems associated with traditional edentulous jaw implant restoration. The benefits of dynamic navigation include fine positioning guidance, restoration-guided surgery, good aesthetic results, and the possibility of simultaneous conceptual design and real-time implant guidance, as well as the transition from "blind" to "direct" vision during the implantation. It can guide clinicians and adjust the plan in real time, improve the efficiency of communication between the clinician, technician, and patient throughout the process and so on. The workflow, current clinical application and challenges, accuracy analysis, and limitations of the dynamic navigation technology in the edentulous jaw are discussed in this paper, as well as an outlook on its future development, with the goal of contributing to the clinical development of dynamic navigation-guided implantology in the edentulous jaw.
Humans ; Dental Implantation, Endosseous/methods* ; Dental Implants ; Surgery, Computer-Assisted/methods* ; Esthetics, Dental ; Jaw, Edentulous/surgery* ; Technology

Objective: To compare cusp and U-tube registration methods of dynamic navigation system in dental implant placement. Methods: Twenty resin mandible models and 40 implants were utilized, with implants being placed by a single researcher using one of the two registration methods selected at random. Accuracy was measured through the superimposition of the final and planned implant positions. Angular deviation, three-dimensional (3D) entry deviation, and 3D apex deviation were analyzed. Results: The 3D entry deviation, and 3D apex deviation and angular deviation of cusp group and U-tube group were (1.07±0.46) and (0.93±0.54) mm, (1.16±0.55) and (1.03±0.53) mm, 2.06°±0.98°and 1.62°±0.97°. No significant differences (t=0.91, P=0.368; t=0.79, P=0.436; t=1.42, P=0.164) were observed when comparing these two registration methods. Conclusions: Both the cusp and U-tube registration methods are highly accurate when implemented in vitro. The cusp registration technique can also overcome several of the limitations of the U-tube approach, and it is convenient for clinic.
Dental Implantation, Endosseous/methods* ; Dental Implants ; Surgery, Computer-Assisted/methods* ; Mandible/surgery* ; Imaging, Three-Dimensional ; Cone-Beam Computed Tomography ; Computer-Aided Design

OBJECTIVE: To investigate the accuracy and safety of pedicle screw placement assisted by orthopedic robot and C-arm fluoroscopy. METHODS: The clinical data of 36 patients with spinal diseases underwent surgical treatment from January 2019 to August 2020 was retrospectively analyzed. Among them, 18 cases were implanted pedicle screws assisted by orthopaedic robot(observation group), including 12 males and 6 females, aged from 16 to 61 years with an average of (38.44±3.60) years;there were 1 case of adolescent scoliosis, 1 case of spinal tuberculosis, 7 cases of lumbar spondylolisthesis, 4 cases of thoracic fracture and 5 cases of lumbar fracture. Another 18 cases were implanted pedicle screws assisted by C-arm fluoroscopy(control group), including 10 males and 8 females, aged from 18 to 58 years with an average of (43.22±2.53) years;there were 1 case of adolescent scoliosis, 6 cases of lumbar spondylolisthesis, 6 cases of thoracic fracture and 5 cases of lumbar fracture. The intraoperative fluoroscopy times, nail placement time and postoperative complications were recorded in two groups. CT scan was performed after operation. The Gertzbein-Robbins standard was used to evaluate the accuracy of pedicle screw placement which was calculated. RESULTS: The number of intraoperative fluoroscopy in observation group was(6.89±0.20) times, which was significantly higher than that in control group(14.00±0.18)times(P<0.05). The placement time of each screw in observation group was(2.56±0.12) min, which was significantly different from that in control group(4.22±0.17) min (P<0.05). One case of incision infection occurred in control group after operation, and recovered after active dressing change. During the follow-up period, no serious complications such as screw loosening and fracture occurred in two groups, and there was no significant difference in complications between two groups(P>0.05). A total of 107 screws were placed in observation group, including 101 screws in class A, 4 in class B, 2 in class C, 0 in class D and 0 in class E, the accuracy rate of pedicle screw placement=[(number of screws in class A+B) / the number of all screws placed in the group] ×100%=98.1%(105/107); and a total of 104 screws were placed in control group, including 90 screws in class A, 4 in class B, 5 in class C, 5 in class D and 0 in class E, the accuracy rate of pedicle screw implantation=[(number of screws in class A+B/the number of all screws placed in the group]×100%=90.3% (94/104); there was significant difference between two groups (P<0.05). CONCLUSION Orthopaedic robot assisted pedicle screw placement has the advantages of less fluoroscopy times, shorter screw placement time and higher accuracy, which can further improve the surgical safety and has a broad application prospect in the orthopaedic.
Adolescent ; Adult ; Female ; Fluoroscopy/methods* ; Humans ; Lumbar Vertebrae/surgery* ; Male ; Middle Aged ; Pedicle Screws ; Retrospective Studies ; Robotic Surgical Procedures/methods* ; Robotics ; Scoliosis ; Spinal Fusion/methods* ; Surgery, Computer-Assisted ; Young Adult