A novel dynamic electromagnetic tracking navigation system for distal locking of intramedullary nails

A multi-view interactive virtual-physical registration method for mixed reality based surgical navigation in pelvic and acetabular fracture fixation

PURPOSE

The treatment of pelvic and acetabular fractures remains technically demanding, and traditional surgical navigation systems suffer from the hand-eye mis-coordination. This paper describes a multi-view interactive virtual-physical registration method to enhance the surgeon's depth perception and a mixed reality (MR)-based surgical navigation system for pelvic and acetabular fracture fixation.

METHODS

First, the pelvic structure is reconstructed by segmentation in a preoperative CT scan, and an insertion path for the percutaneous LC-II screw is computed. A custom hand-held registration cube is used for virtual-physical registration. Three strategies are proposed to improve the surgeon's depth perception: vertices alignment, tremble compensation and multi-view averaging. During navigation, distance and angular deviation visual cues are updated to help the surgeon with the guide wire insertion. The methods have been integrated into an MR module in a surgical navigation system.

RESULTS

Phantom experiments were conducted. Ablation experimental results demonstrated the effectiveness of each strategy in the virtual-physical registration method. The proposed method achieved the best accuracy in comparison with related works. For percutaneous guide wire placement, our system achieved a mean bony entry point error of 2.76 ± 1.31 mm, a mean bony exit point error of 4.13 ± 1.74 mm, and a mean angular deviation of 3.04 ± 1.22°.

CONCLUSIONS

The proposed method can improve the virtual-physical fusion accuracy. The developed MR-based surgical navigation system has clinical application potential. Cadaver and clinical experiments will be conducted in future.

Global research status and trends in orthopaedic surgical robotics: a bibliometric and visualisation analysis study

This study aimed to investigate and summarise the current state of research and trends in orthopaedic surgical robots. Data on publicly available publications related to orthopaedic surgical robots were extracted by abstract searches of the Web of Science Core Collection database. A bibliometric analysis and detailed reading of the publications were then carried out and the information was visualised using co-authorship analysis, coupling analysis, co-citation analysis and co-occurrence analysis in VOSviewer. With 436 publications included in the study from 1993 to 2022, the overall contribution of publications to the world showed an increasing trend year by year, with a particularly pronounced after 2017, and a geographical trend of predominantly East Asia, North America, and Western Europe. Of these, China was the largest contributor (n = 128). Overall, the UK affiliates and their scholars were leaders in the field, with a high number of publications, total citations, average citations per article and H-index. The most published institutions and authors were Imperial College London (n = 21) and Professor Fares Sahi Haddad of University College London (n = 12), respectively. Journals with a high overall impact on robotic orthopaedic surgery were the Journal of Arthroplasty, Bone Joint Journal, International Journal of Medical Robotics and Computer Assisted Surgery. Keyword co-occurrence network analysis revealed four main clusters: robot-assisted knee, hip arthroplasty, spine surgery, and robotic technology research and development. The top three most common sites for robot-assisted surgery use were the knee, hip and spine. The most used robot types were the knee and spine, with Mako and Arobot being the most used robots for the knee and TiRobot for the spine. This study comprehensively reveals the current status and trends of global research on orthopaedic surgical robots, covering countries, institutions, authors, journals, research hotspots, robot types and surgical sites, providing directional guidance and research ideas for further research on the technological development and clinical evaluation of orthopaedic surgical robots.

Determination of intramedullary nail based on centerline adaptive registration

Objective: Internal fixation with intramedullary nails is a gold standard for the treatment of femoral shaft fractures. However, both the mismatch between intramedullary nails and the medullary cavity and inaccurate positioning of entry points will lead to deformation of intramedullary nails after implantation. The study aimed to determine a suitable intramedullary nail with an optimal entry point for a specific patient based on centerline adaptive registration.

Method: A homotopic thinning algorithm is employed to extract centerlines of the femoral medullary cavity and the intramedullary nail. The two centerlines are registered to obtain a transformation. The medullary cavity and the intramedullary nail are registered based on the transformation. Next, a plane projection method is employed to calculate the surface points of the intramedullary nail laid outside the medullary cavity. According to the distribution of compenetration points, an iterative adaptive registration strategy is designed to decide an optimal position of the intramedullary nail in medullary cavity. The isthmus centerline is extended to the femur surface, where the entry point of the intramedullary nail is located. The suitability of an intramedullary nail for a specific patient was calculated by measuring the geometric quantities reflecting the interference between the femur and nail, and the suitability values of all nails are compared and the most suitable one is determined.

Results: The growth experiment indicated that the bone to nail alignment is indeed affected by the extension of the isthmus centerline, including the extension direction and velocity. The geometrical experiment showed that this method could find the best registration position of intramedullary nails and select the optimal intramedullary nail for a specific patient. In the model experiments, the determined intramedullary nail could be successfully placed into the medullary cavity through the optimal entry point. A pre-screening tool to determine nails which can be successfully used has been given. In addition, the distal hole was accurately located within 14.28 s.

Conclusion: These results suggest that the proposed method can select a suitable intramedullary nail with an optimal entry point. The position of the intramedullary nail can be determined in the medullary cavity, while deformation is avoided. The proposed method can determine the largest diameter intramedullary nail with as little damage to the intramedullary tissue as possible. The proposed method provides preparation aid for internal fixation with intramedullary nails guided by navigation systems or extracorporeal aimers.

A review of advances in image-guided orthopedic surgery

Orthopedic surgery remains technically demanding due to the complex anatomical structures and cumbersome surgical procedures. The introduction of image-guided orthopedic surgery (IGOS) has significantly decreased the surgical risk and improved the operation results. This review focuses on the application of recent advances in artificial intelligence (AI), deep learning (DL), augmented reality (AR) and robotics in image-guided spine surgery, joint arthroplasty, fracture reduction and bone tumor resection. For the pre-operative stage, key technologies of AI and DL based medical image segmentation, 3D visualization and surgical planning procedures are systematically reviewed. For the intra-operative stage, the development of novel image registration, surgical tool calibration and real-time navigation are reviewed. Furthermore, the combination of the surgical navigation system with AR and robotic technology is also discussed. Finally, the current issues and prospects of the IGOS system are discussed, with the goal of establishing a reference and providing guidance for surgeons, engineers, and researchers involved in the research and development of this area.