Surgical Stabilisation of Rib Fractures (SSRF) is a critical procedure performed in trauma care to manage severe rib fractures. Accurate localisation of the fractures is vital, as misplacement of the incision can lead to excessive tissue dissection, longer recovery times and increased postoperative complications. Conventional methods for rib fracture localisation rely primarily on preoperative computed tomography (CT) imaging and ultrasound (US). However, both techniques present significant limitations. CT imaging requires surgeons to mentally map fracture locations from a screen onto the patient’s body, which can be complex due to differences in patient positioning during scanning and surgery. US, though capable of real-time imaging, can be limited by patient body morphology and is prone to inaccuracies when fractures are obscured by anatomical structures or in certain body areas.
RibMR, a mixed reality (MR) visualisation system, aims to overcome these limitations by providing a real-time 3D holographic projection of the patient's ribcage directly onto their body during surgery. This innovative system offers improved accuracy and efficiency for rib fracture localisation, potentially enhancing surgical outcomes and reducing postoperative complications. A recent study published in the Journal of Imaging Informatics in Medicine explores the development, validation and clinical impact of RibMR through phantom, preclinical and clinical trials, demonstrating its advantages over traditional approaches.
RibMR Technology and Development
RibMR was designed to address the limitations associated with traditional imaging techniques for rib fracture localisation in trauma surgery. It employs a mixed reality headset, the Microsoft HoloLens 2, which overlays a 3D holographic model of the patient’s ribcage onto their body. This model is constructed from standard CT images and segmented using advanced imaging algorithms to create a detailed and patient-specific visualisation.
The system incorporates a semi-automatic alignment process using five bony landmarks and a Singular Value Decomposition (SVD) algorithm. This ensures the holographic model aligns accurately with the patient’s actual anatomy without requiring modifications to standard CT scanning protocols, making it suitable for emergency trauma settings. The hardware setup consists of the HoloLens 2 headset, a laptop for model preparation and a portable cart, ensuring flexibility and ease of use in different surgical environments.
Unlike conventional imaging methods, RibMR minimises the need for mental mapping by allowing the surgeon to visualise the fractures directly on the patient’s body, reducing the risk of incision errors and extensive tissue disruption. The development of RibMR was guided by the requirements of SSRF, focusing on intuitive usability, compatibility with standard CT imaging and minimal disruption to existing surgical workflows.
Validation Through Phantom, Preclinical and Clinical Studies:
RibMR underwent a rigorous three-phase validation process comprising phantom, preclinical and clinical studies to assess its accuracy, speed and usability compared with ultrasound.
The phantom study used a human mannequin with artificial rib fractures marked by metal washers. RibMR achieved an average localisation accuracy of 0.38 cm and a 100% localisation rate of the simulated fractures.
Preclinical trials involved two healthy volunteers without rib fractures. Surgeons used RibMR to identify simulated rib fractures marked on the patient's skin. The average localisation accuracy was 3.75 cm, and RibMR achieved a 91.67% localisation rate.
In the clinical phase, RibMR was tested on two trauma patients requiring SSRF. The system achieved an average localisation accuracy of 1.47 cm, outperforming ultrasound, identifying only 56% of the fractures compared to RibMR’s 88%. Additionally, RibMR identified fractures not visible using US, such as those obscured by anatomical structures.
Speed measurements showed RibMR also improved efficiency, with an average localisation time of 8.76 minutes compared to 9.99 minutes for US in clinical trials. Faster identification of fracture sites can reduce overall surgery time, contributing to better patient outcomes.
Clinical Impact and Advantages:
RibMR offers several significant advantages for rib fracture localisation in SSRF, positioning it as a promising alternative to traditional methods.
One of the system’s primary strengths is its ability to provide real-time, patient-specific holographic visualisation, reducing the cognitive burden on surgeons who would otherwise have to mentally map CT scans onto the patient’s anatomy. This direct visualisation improves localisation accuracy, particularly in areas where US can struggle, such as the subscapular region or in patients with complex body morphologies.
RibMR also minimises the need for large surgical incisions and excessive tissue dissection by improving fracture localisation accuracy. This can lead to smaller incisions, reducing postoperative pain, infection risks and recovery times.
Another advantage is the system’s speed and efficiency. RibMR’s ability to localise fractures faster than US can reduce surgical durations and the time a patient spends under anaesthesia, which can lower overall surgical risks.
Furthermore, RibMR’s technology is portable and adaptable for various surgical settings. Its compatibility with standard CT imaging protocols and trauma workflows ensures minimal disruption to clinical practice, making it an attractive tool for high-pressure trauma environments.
RibMR presents a transformative approach to rib fracture localisation in SSRF, offering improved accuracy, speed and fracture identification rates compared to ultrasound. Its use of mixed reality technology, combined with a patient-specific holographic model, addresses many limitations of traditional imaging techniques.
The successful results from phantom, preclinical and clinical studies suggest that RibMR has significant potential to enhance surgical precision while reducing complications associated with rib fracture surgeries. Further studies with larger patient groups and additional refinements to the technology will be essential to fully realise its benefits. However, RibMR's performance to date demonstrates a clear advantage in trauma care, making it a promising tool for improving surgical outcomes and patient care.
Source: Journal of Imaging Informatics in Medicine
Image Credit: iStock
