Use of 3D Navigation Versus Traditional Fluoroscopy for Posterior Pelvic Ring Fixation

FFP: Indication for minimally invasive navigation technique

An 85-year-old female patient was transferred to our clinic for surgical treatment of a complex FFP IIc. She had suffered a ground level fall 10 days ago and was still living independently. The patient was initially treated conservatively with pain medication and immobilization in an outward hospital. Due to the clinical symptoms and complex fracture pattern a physiotherapeutic assisted mobilization was not possible. The clinical examination revealed severe bilateral pain at the anterior and posterior pelvic ring. We performed a minimally invasive and an image-guided surgical stabilization. After surgical treatment the patient was mobilized with crutches for short distances. On the third day after surgical intervention the patient was discharged from our hospital into rehabilitation. This case shows the successful use of minimally invasive and modern navigation technique for treatment of a complex FFP.

Imaging, post-processing and navigation: Surgical applications in pelvic fracture treatment

Technical advancements of the past decade have led to massive improvements regarding imaging and visualization in trauma care. Digital imaging technology has fundamentally changed most processes in fracture management. However, the digital revolution in trauma surgery has just begun. Optical tracking navigation is currently the gold standard for positioning of implants for advanced applications in trauma surgery. Digital technology may enable the surgeon to achieve the same level of safety even in non-navigated placement of screws: We developed a new planning tool to transcript a preoperative into a semi-transparent "fluoroscopic like" image that can be identified intraoperatively and used as a map for the safe placement of sacro-iliac screws based on the "vestibule concept". In the future, development of artificial intelligence algorithms may provide features like automated segmentation of bone-fragments and other applications for a systematic fracture analysis to improve the standard of care in trauma surgery. Digital transformation has massive impact on diagnostics and surgical management of pelvic fractures. Improved visualization technology provides a better understanding of the surgical anatomy of the pelvis and may enable the surgeon to achieve greatest safety in percutaneous placement of screws even without using optical tracking navigation tools. The "para-axial fusion technique" is a useful tool to plan fluoroscopic views based on a 3D dataset prior to the surgery.

[Preliminary application study of dual-robotic navigated minimally invasive treatment by TiRobot and Artis Zeego on pelvic fractures]

Objective

To summarize the surgical learning curve and preliminary operative experience of dual-robotic navigated minimally invasive treatment on pelvic fractures by TiRobot and Artis Zeego.

Methods

Between July 2019 and February 2021, 90 patients with pelvic fractures were treated with dual-robotic navigated minimally invasive surgery by TiRobot and Artis Zeego. There were 64 males and 26 females, with an average age of 46.5 years (range, 13-78 years). Body mass index was 14.67-32.66 kg/m ² (mean, 23.61 kg/m ²). Causes of injuries included traffic accident in 43 cases, falling from height in 37 cases, low-energy injuries such as flat falls in 10 cases. The interval between injury and surgery was 1-36 days (mean, 7.3 days). According to the location of the implanted screws, the patients were divided into sacroiliac screw group ( n=33), acetabular screw group (acetabulum anterior/posterior column, n=24), composite screws group (sacroiliac and acetabulum anterior/posterior column, n=33). According to the screw implantation time and accuracy, the surgical learning curve was plotted, and the differences in the relevant indicators between learning stage and skilled stage were compared.

Results

All 90 patients successfully completed the operation, the intraoperative bleeding volume was 5-200 mL (median, 20 mL). There was no vascular or nerve injury. All incisions healed by first intention. The screw implantation time ranged from 7.5 to 33.0 minutes (mean, 18.92 minutes), and the screw implantation accuracy ranged from 1.1 to 1.8 mm (mean, 1.56 mm). According to the learning curve, the practice stage of 3 groups was reached after 7, 10, and 11 cases, respectively. With the accumulation of surgical experience, the screw implantation time had a significant downward trend. Compared with the learning stage, the screw implantation time on skilled stage in 3 groups significantly shortened ( P<0.05), but the difference in the screw implantation accuracy was not significant ( P>0.05).

Conclusion

TiRobot and Artis Zeego assisted pelvic fracture surgery is safe and efficient, which helps the surgeon to quickly master the pelvic channel screw surgery, and the operation time is significantly shortened on the premise of ensuring the implantation accuracy.

Design and evaluation of an intelligent reduction robot system for the minimally invasive reduction in pelvic fractures

Introduction

Pelvic fracture is a severe high-energy injury with the highest disability and mortality of all fractures. Traditional open surgery is associated with extensive soft tissue damages and many complications. Minimally invasive surgery potentially mitigates the risks of open surgical procedures and is becoming a new standard for pelvic fracture treatment. The accurate reduction has been recognized as the cornerstone of minimally invasive surgery for pelvic fracture. At present, the closed reduction in pelvic fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces of soft tissue involved in the fragment manipulation, which might result in fracture malreduction. To overcome these shortcomings and facilitate pelvic fracture reduction, we developed an intelligent robot-assisted fracture reduction (RAFR) system for pelvic fracture.

Methods

The presented method is divided into three parts. The first part is the preparation of 20 pelvic fracture models. In the second part, we offer an automatic reduction algorithm of our robotic reduction system, including Intraoperative real-time 3D navigation, reduction path planning, control and fixation, and robotic-assisted fracture reduction. In the third part, image registration accuracy and fracture reduction accuracy were calculated and analyzed.

Results

All 20 pelvic fracture bone models were reduced by the RAFR system; the mean registration error E1 of the 20 models was 1.29 ± 0.57 mm. The mean reduction error E2 of the 20 models was 2.72 ± 0.82 mm. The global error analysis of registration and reduction results showed that higher errors are mainly located at the edge of the pelvis, such as the iliac wing.

Conclusion

The accuracy of image registration error and fracture reduction error in our study was excellent, which could reach the requirements of the clinical environment. Our study demonstrated the precision and effectiveness of our RAFR system and its applicability and usability in clinical practice, thus paving the way toward robot minimally invasive pelvic fracture surgeries.