Computer-assisted Surgery Research Articles

Application of Artificial Intelligence (AI) on improving accuracy of dental implant placement using Computer-Assisted Implant Surgery (CAIS)

Tooth loss is one of the most common oral health problems, and may affect mastication, phonetics, aesthetics, and quality of life. Dental implant placement is an effective procedure to replace tooth loss. Dental implant placement techniques using freehand surgery procedures increase potential failure related to position, angle, and depth of insertion with 6.42% failure prevalence. The accuracy of installing dental implants through freehand protocol depends on the ability and experience of the doctor. New innovations such as using Artificial Intelligence (AI) in Computer-Assisted Implant Surgery (CAIS) have been developed to improve the accuracy of dental implant placement. This article review uses a method finding theories from research journals and case reports with keywords "dental implant", "artificial intelligence", "computer-assisted surgery" on Google Scholar and Pubmed, five (5) research journals and one (1) case reports met requirements to be discussed. Application Artificial Intelligence (AI) in CAIS, through 3D Standard Tessellation Language (STL) planning on Cone Beam Computed Tomography (CBCT) segmentation and alignment with Intra-Oral Scanner (IOS). 3D planning is a holographic environment. CAIS are divided into static and dynamic. The static procedure performed by printing stereolithographic guide from the dental implant placement for the operator, the dynamic procedure when the operator sees in real-time the position, angulation, and drilling depth on a screen. The results showed that there was a slight deviation between the position, angulation, and depth of the implant during planning and post-surgery. Artificial Intelligence (AI) applications using Computer-Assisted Implant Surgery (CAIS) can improve the accuracy of dental implant placement.

A quantitative comparison of bone resection margin distances in virtual surgical planning versus histopathology: a prospective study.

Positive bone margins have been shown to be associated with worse locoregional control and survival performance in oral oncology patients. With the application of computer-assisted surgery and patient-specific surgical guides, the authors can accurately execute the preoperative osteotomy plan. However, how well the authors can predict the margin distance in the final histopathology with a preoperative computed tomography (CT) scan, the factors associated with it, and how much leeway CT should spare when designing the osteotomy planes during virtual surgical planning (VSP) remain to be investigated. Patients from January 2021 to December 2022 with benign or malignant jaw tumors and with signs of bone marrow involvement in the preoperative CT scan in our center were prospectively recruited to the study. VSP and measurement of the closest margin distance in the CT scan were performed by the single team of surgeons. The resection specimen was processed, and the margin distances were measured by a dedicated senior pathologist with the knowledge of orientation of the osteotomy planes. A total of 35 patients were recruited, with 21 malignant and 14 benign cases. Sixty-eight bone margins were quantitatively analyzed. No significant difference in margin distances measured from the CT scan and final histopathology was detected ( P =0.19), and there was a strong correlation between the two (r s =0.74, P <0.01). A considerable amount of variance was detected in the level of discrepancy between margin distances measured in the CT scan and final histopathology (overall SD=6.26 mm, malignancy SD=7.44 mm, benign SD=4.40 mm). No significant correlation existed between the two margin distances when only maxilla tumor margins were assessed ( P =0.16). The bone margin distance in VSP is reliably correlated to the final pathological margin distance. A leeway distance of 15mm and 9mm should be considered when designing the osteotomy planes for malignancy and benign cases, respectively. Extra attention should be paid to maxilla cases when predetermining the osteotomy planes during VSP.

Experience of use of the individual cutting block «5 in 1» using total knee arthroplasty

BACKGROUND: Total knee arthroplasty is the most progressively developing direction in the modern orthopaedic world. With the new visualization technologies, a whole new field of computer-assisted orthopaedic surgery has emerged. Generally, three groups can be distinguished in computer-assisted orthopedic surgery. The 1st group the use of individual resection blocks, templates or guides remains the most relevant today. However, the use of currently existing individual resection blocks, according to the literature, has contradictory results.&#x0D; CLINICAL CASES DESCRIPTION: This work presents the author's developed technique of a new preoperative 3D modeling for total knee arthroplasty using individual resection blocks. The paper presents a clinical case demonstrating the effectiveness of the new technique.&#x0D; CONCLUSION: The strategy CT+MRI, in our opinion, is the optimal solution not only for competent preoperative planning of total knee arthroplasty, but also for designing individual resection blocks. Our individual resection blocks allowed us to improve the accuracy of total knee arthroplasty.

How Is a Cutting Guide With Additional Anatomical References Better in Fibular-Free Flap Mandibular Reconstruction? A Technical Strategy.

Computer-assisted surgery is used to design and manufacture cutting guides in mandibular reconstructions with fibula-free flaps. To improve the outcomes of the procedure, the aim of this research was to investigate and compare the accuracy of mandibular reconstruction following the use of 2 versus 3 anatomical reference cutting guides. Eighteen sets of prototype bone models retrieved from an ameloblastoma patient were used for mock operations. The mandibular segmental osteotomies and fibular reconstructions were performed using 2 and 3 anatomical reference cutting guides in vivo surgeries. After reconstruction, the accuracy of the placed reference points was measured by superimposition of computed tomography images. The error in cutting guides when using 2 or 3 anatomical references showed no significant difference. The fibular and condylar errors of the cutting guide between 2 and 3 anatomical references showed no significant difference in every plate type. The difference in screw hole position errors between 2 and 3 anatomical reference cutting guides was not statistically significant. Two anatomical reference cutting guides are sufficient and reasonable enough for mandible resection. However, there were some limitations and errors in our study.

Robotics and navigation in spine surgery: A narrative review

IntroductionIn recent decades, there has been a rising trend of spinal surgical interventional techniques, especially Minimally Invasive Spine Surgery (MIS), to improve the quality of life in an effective and safe manner. However, MIS techniques tend to be difficult to adapt and are associated with an increased risk of radiation exposure. This led to the development of ‘computer-assisted surgery’ in 1983, which integrated CT images into spinal procedures evolving into the present day robotic-assisted spine surgery. The authors aim to review the development of spine surgeries and provide an overview of the benefits offered. It includes all the comparative studies available to date. MethodsThe manuscript has been prepared as per “SANRA-a scale for the quality assessment of narrative review articles”. The authors searched Pubmed, Embase, and Scopus using the terms “(((((Robotics) OR (Navigation)) OR (computer assisted)) OR (3D navigation)) OR (Freehand)) OR (O-Arm)) AND (spine surgery)” and 68 articles were included for analysis excluding review articles, meta-analyses, or systematic literature. ResultsThe authors noted that 49 out of 68 studies showed increased precision of pedicle screw insertion, 10 out of 19 studies show decreased radiation exposure, 13 studies noted decreased operative time, 4 out of 8 studies showed reduced hospital stay and significant reduction in rates of infections, neurological deficits, the need for revision surgeries, and rates of radiological ASD, with computer-assisted techniques. ConclusionComputer-assisted surgeries have better accuracy of pedicle screw insertion, decreased blood loss and operative time, reduced radiation exposure, improved functional outcomes, and lesser complications.

Learning curve for robot-assisted knee arthroplasty; optimizing the learning curve to improve efficiency.

The introduction of robot-assisted (RA) systems in knee arthroplasty has challenged surgeons to adopt the new technology in their customized surgical techniques, learn system controls, and adjust to automated processes. Despite the potential advantages of RA knee arthroplasty, some surgeons remain hesitant to adopt this novel technology owing to concerns regarding the cumbersome adaptation process. This narrative review addresses the learning-curve issues in RA knee arthroplasty based on the existing literature. Learning curves exist in terms of the operative time and stress level of the surgical team but not in the final implant positions. The factors that reduce the learning curve are previous experience with computer-assisted surgery (including robot or navigation systems), specialization in knee surgery, high volume of knee arthroplasty, optimization of the RA workflow, sequential implementation of RA surgery, and consistency of the surgical team. Worse clinical outcomes may occur in the early postoperative period, but not in the later period, in RA knee arthroplasty performed during the learning phase. No significant differences were observed in implant survival or complication rates between the RA knee arthroplasties performed during the learning and proficiency phases.

Image-to-Patient Registration in Computer-Assisted Surgery of Head and Neck: State-of-the-Art, Perspectives, and Challenges.

Today, image-guided systems play a significant role in improving the outcome of diagnostic and therapeutic interventions. They provide crucial anatomical information during the procedure to decrease the size and the extent of the approach, to reduce intraoperative complications, and to increase accuracy, repeatability, and safety. Image-to-patient registration is the first step in image-guided procedures. It establishes a correspondence between the patient's preoperative imaging and the intraoperative data. When it comes to the head-and-neck region, the presence of many sensitive structures such as the central nervous system or the neurosensory organs requires a millimetric precision. This review allows evaluating the characteristics and the performances of different registration methods in the head-and-neck region used in the operation room from the perspectives of accuracy, invasiveness, and processing times. Our work led to the conclusion that invasive marker-based methods are still considered as the gold standard of image-to-patient registration. The surface-based methods are recommended for faster procedures and applied on the surface tissues especially around the eyes. In the near future, computer vision technology is expected to enhance these systems by reducing human errors and cognitive load in the operating room.

The Value of Computer-Assisted Navigation for Glenoid Baseplate Implantation in Reverse Shoulder Arthroplasty: A Systematic Review and Meta-Analysis.

Glenoid baseplate malpositioning during reverse total shoulder arthroplasty can contribute to perimeter impingement, dislocation, and loosening. Despite advances in preoperative planning, conventional instrumentation may lead to considerable inaccuracy in implant positioning unless patient-specific guides are used. Optical navigation has the potential to improve accuracy and precision when implanting a reverse shoulder arthroplasty baseplate. This systematic review aimed to analyze the most recent evidence on the accuracy and precision of glenoid baseplate positioning using intraoperative navigation and its potential impact on component selection and surgical time. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. The PubMed, Scopus, and EMBASE databases were queried in July 2022 to identify all studies that compared navigation vs. conventional instrumentation for reverse shoulder arthroplasty. Data of deviation from the planned baseplate version and inclination, the use of standard or augmented glenoid components, and surgical time were extracted. Quantitative analysis from the included publications was performed using the inverse-variance approach and Mantel-Haenszel method. Of the 2,048 records identified in the initial query, only 10 articles met the inclusion and exclusion criteria, comprising 667 shoulders that underwent reverse total shoulder arthroplasty. The pooled mean difference (MD) of the deviation from the planned baseplate position for the clinical studies was -0.44 (95% confidence interval [CI], -3.26; p = 0.76; I2 = 36%) for version and -8.75 (95% CI, -16.83 to -0.68; p = 0.02; I2 = 83%) for inclination, both in favor of navigation. The odds ratio of selecting an augmented glenoid component after preoperative planning and navigation-assisted surgery was 8.09 (95% CI, 3.82-17.14; p < 0.00001; I2 = 60%). The average surgical time was 12 minutes longer in the navigation group (MD 12.46, 95% CI, 5.20-19.72; p = 0.0008; I2 = 71%). Preoperative planning integrated with computer-assisted navigation surgery seems to increase the accuracy and precision of glenoid baseplate inclination compared with the preoperatively planned placement during reverse total shoulder arthroplasty. The surgical time and proportion of augmented glenoid components significantly increase when using navigation. However, the clinical impact of these findings on improving prosthesis longevity, complications, and patient functional outcomes is still unknown. Level III, systematic review and meta-analysis. See Instructions for Authors for a complete description of levels of evidence.

Computer-assisted surgery for placing toggle constructs across the coxofemoral joints of small equids using a minimally invasive approach-A proof-of-concept cadaveric study.

To develop a minimally invasive technique for placing a toggle construct across the coxofemoral joint of small equids using computer-assisted surgery. Experimental cadaveric study. Three pilot specimens: One donkey, one Shetland pony and one Warmblood foal. Six main study specimens: Three Shetland ponies, one American Miniature Horse, one Warmblood foal and one donkey. Experimental surgeries were performed on both coxofemoral joints of each cadaver. Using a minimally invasive surgical approach, 5.5 mm bone canals were drilled through the femur and acetabulum, traversing the coxofemoral joint. Intraoperative guidance was provided by a cone-beam computed tomography (CBCT)-coupled surgical navigation system. A toggle construct was introduced through the bone canals. Surgical accuracy aberrations (SAA) were measured at the femoral entry and exit points and at the acetabular entry point on merged pre- and postoperative CBCT scans. The coxofemoral joint was assessed for articular cartilage damage by gross dissection. A toggle construct was placed across all 18 coxofemoral joints. The overall median SAA in the main study was 2.8 mm (range: 0.4-8.0 mm). No cartilage damage was found in the cadaveric specimens of the main study. The described technique allowed for the placement of a toggle construct across the coxofemoral joint of small equid cadaveric specimens without prior coxofemoral luxation. This technique may serve as an option for surgical stabilization of coxofemoral joints in small equids. Further biomechanical investigations are required to assess optimal implant positioning and toggle constructs.

Accuracy of hard and soft tissue prediction using three-dimensional simulation software in bimaxillary osteotomies: A systematic review

Orthognathic surgery is considered nowadays as a revolutionary treatment option for treating skeletal discrepancies and severe malocclusions in the sagittal, vertical and transverse dimensions. This surgery allows both the restoration of facial harmony and the achievement of satisfactory dental occlusion. The technology of computer-assisted surgeries including virtual surgical simulation programs and planning software greatly contributes to providing a three-dimensional simulation and precise mobilization of the maxilla and/or mandible, thus allowing the prediction of the final outcome in soft tissues. This study aims to systematically review the available scientific literature about the accuracy of the hard and soft tissue predictions delivered by the many promoted three-dimensional simulation software. An electronic search was conducted on various databases: Medline via PubMed, The Cochrane Library, EBSCO-host, and Web of Science. The search was established on a well-defined research question following PICO principle: population, intervention, comparator and outcome. Search evaluation and the assessment of risk of bias were undertaken in each study following its type and design. Fifteen studies were included for qualitative analysis. Seven studies evaluated the accuracy of soft tissue prediction, seven focused more on the accuracy of hard tissue and one study assessed both hard and soft tissue prediction accuracy delivered by the simulation software. Moreover, three studies were judged to be low risk and four were classified as high risk. Included studies revealed that hard tissue prediction is highly accurate and reliable, leading to clinically acceptable results. Yet, soft tissue prediction is unclear due to various factors that bias its results. Caution should therefore be taken when providing information about the soft tissue planning to patients. Computer assisted 3D simulation protocols allow for more precise repositioning of the maxilla and/or mandible compared to conventional 2D methods. However, 3D soft tissue prediction using simulation software remains less accurate, especially in the labial region.

Accuracy of on-site teleoperated milling with haptic assistance

PurposeIn bone surgery specialties, like orthopedics, neurosurgery, and oral and maxillofacial surgery patient safety and treatment success depends on the accurate implementation of computer-based surgical plans. Unintentional plan deviations can result in long-term functional damage to the patient. With on-site teleoperation, the surgeon operates a slave robot with a physically-decoupled master device, while being directly present at the operation site. This allows the surgeon to perform surgical tasks with robotic accuracy, while always remaining in the control loop.MethodsIn this study the master- and slave-side accuracy of an on-site teleoperated miniature cooperative robot (minaroHD) is evaluated. Master-side accuracy is investigated in a user study regarding scale factor, target feed rate, movement direction and haptic guidance stiffness. Scale factors are chosen to correspond to primarily finger, hand, and arm movements. Slave-side accuracy is investigated in autonomous milling trials regarding stepover, feed rate, movement direction, and material density.ResultsMaster-side user input errors increase with increasing target feed rate and scale factor, and decrease with increasing haptic guidance stiffness. Resulting slave-side errors decrease with increasing scale factor and are < 0.07 mm for optimal guidance parameters. Slave-side robot position errors correlate with the feed rate but show little correlation with stepover distance. For optimal milling parameters, the 95th percentile of tracked slave-side position error is 0.086 mm with a maximal error of 0.16 mm.ConclusionFor optimal guidance and milling parameters, the combined error of 0.23 mm is in the range of the dura mater thickness (< 0.27 mm) or mandibular canal wall (~ 0.85 mm). This corresponds to safety margins in high-demand surgical procedures like craniotomies, laminectomies, or decortication of the jaw. However, for further clinical translation, the performance and usability of on-site teleoperated milling must be further evaluated for real-life clinical application examples with consideration of all error sources in a computer-assisted surgery workflow.

Disparity refinement framework for learning-based stereo matching methods in cross-domain setting for laparoscopic images.

Stereo matching methods that enable depth estimation are crucial for visualization enhancement applications in computer-assisted surgery. Learning-based stereo matching methods have shown great promise in making accurate predictions on laparoscopic images. However, they require a large amount of training data, and their performance may be degraded due to domain shifts. Maintaining robustness and improving the accuracy of learning-based methods are still open problems. To overcome the limitations of learning-based methods, we propose a disparity refinement framework consisting of a local disparity refinement method and a global disparity refinement method to improve the results of learning-based stereo matching methods in a cross-domain setting. Those learning-based stereo matching methods are pre-trained on a large public dataset of natural images and are tested on two datasets of laparoscopic images. Qualitative and quantitative results suggest that our proposed disparity framework can effectively refine disparity maps when they are noise-corrupted on an unseen dataset, without compromising prediction accuracy when the network can generalize well on an unseen dataset. Our proposed disparity refinement framework could work with learning-based methods to achieve robust and accurate disparity prediction. Yet, as a large laparoscopic dataset for training learning-based methods does not exist and the generalization ability of networks remains to be improved, the incorporation of the proposed disparity refinement framework into existing networks will contribute to improving their overall accuracy and robustness associated with depth estimation.

Both-column Acetabular Fractures with Posterior Wall Involved can be Managed through Single Anterior Approach by Evaluation of Computer-assisted Virtual Surgery Technique.

Posterior wall (PW) fractures were sometimes associated in both-column acetabular fractures. How to evaluate pre-operatively the necessity for the performance of the posterior approach was an issue to be solved. In order to solve this issue, the computer-assisted virtual surgery technique was used to evaluate if the involved PW in both-column acetabular fractures (BACF) should be managed through posterior approach and verify the feasibility of this method. Data of a consecutive cohort of 72 patients with both-acetabular fractures from January 2012 to January 2020 was collected for retrospective study, of which 44 patients had concomitant acetabular PW fractures, and patients without PW fractures were labeled as the BCAF group. Computer-assisted virtual surgery technique was performed pre-operatively to evaluate the necessity for performance of posterior approach in 44 patients, and posterior approach was required if more than 3 mm of displacement was still present in the reduced 3D model. The 23 patients without treatment through posterior approach were labeled as the BCAF-PW- group, and the 21 patients with treatment through posterior approach were labeled as the BCAF-PW+ group. Operation-related and post-operative parameters were recorded. The quality of reduction and functional outcomes were assessed by the Matta scoring system and modified Merle d'Aubigné and Postel scoring system. The measurement data were analyzed using the t-test of independent samples and rank-sum test of ranked data between every two groups. Also, the one-way analysis of variance (ANOVA) was used to analyze data between the three groups. Comparing operation-related and post-operative parameters in the three groups, some PW fractures in both-column acetabular fractures could be ignored, and which could be evaluated pre-operatively for necessity of an additional posterior approach. Operative time (271.2 ± 32.8 mins) and intra-operative blood loss (1176.7 ± 211.1 mL) were significantly higher in the BCAF-PW+ group. The excellent/good of reduction (25/28 of the BCAF group, 21/23 of the BCAF-PW- group, 19/21 of the BCAF-PW+ group) and functional outcomes (24/28 of the BCAF group, 18/23 of the BCAF-PW- group, 18/21 of the BCAF-PW+ group) of three groups were similar. The incidence of complications, such as deep vein thrombosis (4/28 of the BCAF group >3/23 of the BCAF-PW- group >1/21 of the BCAF-PW+ group) and injury of lateral femoral cutaneous nerve (3/23 of the BCAF-PW- group >2/28 of the BCAF group >0/21 of the BCAF-PW+ group), was no significant difference. The partial both-column acetabular fractures with PW involvement could be managed through a single anterior approach without another posterior approach by evaluation of computer-assisted virtual surgery technique.

Fast and precise collision detection for detailed and complex physiological structures

Background and objectivesVirtual reality has been proved indispensable in computer-assisted surgery, especially for surgical planning, and simulation systems. Collision detection is an essential part of surgery simulators and its accuracy and computational efficiency play a decisive role in the fidelity of simulations. Nevertheless, current collision detection methods in surgical simulation and planning struggle to meet precise requirements, especially for detailed and complex physiological structures. To address this, the primary objective of this study was to develop a new algorithm that enables fast and precise collision detection to facilitate the improvement of the realism of virtual reality surgical procedures. MethodsThe method consists of two main parts, bounding spheres formation and two-level collision detection. A specified surface subdivision method is devised to reduce the radius of basic bounding spheres formed by circumcenters of underlying triangles. The spheres are then clustered and adjusted to obtain a compact personalized hierarchy whose position is updated in real time during surgical simulation, followed by two-level collision detection. Triangular facets with collision potential through interaction between hierarchies and then accurate results are obtained by means of precise detection phase. The effectiveness of the algorithm was evaluated in various models and surgical scenarios and was compared with prior relevant implementations. ResultsResults on multiple models demonstrated that the method can generate a personalized hierarchy with fewer and smaller bounding spheres for tight wrapping. Simulation experiments proved that the proposed approach is significantly superior to comparable methods under the premise of error-free detection, even for severe model-model collision. ConclusionsThe algorithm proposed through this study enables higher numerical efficiency and detection accuracy, which is capable of significantly enlarging the fidelity/realism of haptic simulators and surgical planning methods.

A survey on oral surgeons to gauge their awareness and adoption of emerging technologies like 3D printing, computer-assisted surgery, and virtual reality in planning and performing surgeries

Abstract Background: This study investigates the awareness and adoption of emerging technologies, including 3D printing, computer-assisted surgery, and virtual reality (VR), among oral surgeons in India. Materials and Methods: A cross-sectional survey was conducted among 500 oral surgeons in India. The survey collected data on awareness, adoption, barriers, facilitators, and perceived benefits of these technologies. A stratified random sampling technique ensured representation across regions and healthcare institutions. Results: The survey found that a significant proportion of oral surgeons in India are aware of these emerging technologies (3D printing: 63.8%, computer-assisted surgery: 52.6%, VR: 44.3%). adoption rates were lower but still noteworthy (3D printing: 31.2%, computer-assisted surgery: 23.8%, VR: 19.6%). Cost and lack of training were identified as major barriers, while improved patient outcomes, enhanced precision, and access to training programs were key facilitators. The majority perceived these technologies as beneficial for patient care (improved outcomes: 84.9%, enhanced precision: 79.2%, overall quality: 73.6%). Conclusion: Oral surgeons in India demonstrate a high level of awareness and positive perceptions regarding emerging technologies, though adoption rates indicate room for growth. addressing cost and training barriers could lead to increased adoption, potentially enhancing patient care.

The Use of Tactile Sensors in Oral and Maxillofacial Surgery: An Overview.

This overview aimed to characterize the type, development, and use of haptic technologies for maxillofacial surgical purposes. The work aim is to summarize and evaluate current advantages, drawbacks, and design choices of presented technologies for each field of application in order to address and promote future research as well as to provide a global view of the issue. Relevant manuscripts were searched electronically through Scopus, MEDLINE/PubMed, and Cochrane Library databases until 1 November 2022. After analyzing the available literature, 31 articles regarding tactile sensors and interfaces, sensorized tools, haptic technologies, and integrated platforms in oral and maxillofacial surgery have been included. Moreover, a quality rating is provided for each article following appropriate evaluation metrics. Many efforts have been made to overcome the technological limits of computed assistant diagnosis, surgery, and teaching. Nonetheless, a research gap is evident between dental/maxillofacial surgery and other specialties such as endovascular, laparoscopic, and microsurgery; especially for what concerns electrical and optical-based sensors for instrumented tools and sensorized tools for contact forces detection. The application of existing technologies is mainly focused on digital simulation purposes, and the integration into Computer Assisted Surgery (CAS) is far from being widely actuated. Virtual reality, increasingly adopted in various fields of surgery (e.g., sino-nasal, traumatology, implantology) showed interesting results and has the potential to revolutionize teaching and learning. A major concern regarding the actual state of the art is the absence of randomized control trials and the prevalence of case reports, retrospective cohorts, and experimental studies. Nonetheless, as the research is fast growing, we can expect to see many developments be incorporated into maxillofacial surgery practice, after adequate evaluation by the scientific community.

Navigation-guided resection of locally advanced midface malignancies. Does it improve the safety of oncologic resection?

IntroductionTreatment of malignant midface tumors is a surgical challenge with an increased difficulty to obtain free surgical margins. The computer assisted surgery (CAS) and intraoperative navigation (ION) can be very helpful in complex midface resections. The main objective of this paper is to evaluate if the ION could improve the rate of free surgical margins in locally advanced midface malignancies. Materials and methodsA retrospective cohort study was performed including 40 patients with a locally advanced malignant midface tumor (T4a/b) surgically treated from September 2016 to September 2022. Patients were divided in two groups, a control group included 20 patients operated on without ION and the study group included 20 patients treated with Navigation assisted surgery. A systematic analysis was performed comparing surgical margins in both groups. ResultsSquamous cell carcinoma was the most common histological type. Oral cavity was the most common primary location.Overall, considering each specimen as an hexahedrium, 240 surgical margins were analyzed. 15 out of 120 margins analyzed in the navigation group (12.5 %) were positive while 30 out of 120 margins analyzed in control group (25 %) were affected (p 0.013).Concerning margin location, the ION group showed less involvement of the upper surface of specimen than in control group (p 0.048). ConclusionNavigation Assisted Surgery seems to improve the rate of free surgical margins in patients with locally advanced midface malignancies, specially concerning involvement of the superior margin. Further studies are recommended to corroborate these results and its potential influence in survival rates.

Contactless surface registration of featureless anatomy using structured light camera: application to fibula navigation in mandible reconstruction.

Mandibular reconstruction using fibula free flap is a challenging surgical procedure. To assist osteotomies, computer-assisted surgery (CAS) can be used. Nevertheless, precise registration is required and often necessitates anchored markers that disturb the patient and clinical flow. This work proposes a new contactless surface-based method adapted to featureless anatomies such as fibula to achieve a fast, precise, and reproducible registration. Preoperatively, a CT-scan of the patient is realized and osteotomies are virtually planned. During surgery, a structured light camera digitizes the fibula. The obtained intraoperative point cloud is coarsely registered with the preoperative model using 3 points defined in the CT-scan and located on the patient's bone with a laser beam. Then, a fine registration is performed using an ICP algorithm. The registration accuracy was evaluated comparing the position of points engraved in a 3D-printed fibula with their position in the registered model and evaluating resulting osteotomies. Accuracy and execution time were compared to a conventional stylus-based registration method. The work was validated in vivo. The experiment performed on a 3D-printed model showed that execution time is equivalent to surface-based registration using a stylus, with a better accuracy (mean TRE of 0.9mm vs 1.3mm using stylus) and guarantee good osteotomies. The preliminary in vivo study proved the feasibility of the method. The proposed contactless surface-based registration method using structured light camera gave promising results in terms of accuracy and execution speed and should be useful to implement CAS for mandibular reconstruction.

TAToo: vision-based joint tracking of anatomy and tool for skull-base surgery.

Tracking the 3D motion of the surgical tool and the patient anatomy is a fundamental requirement for computer-assisted skull-base surgery. The estimated motion can be used both for intra-operative guidance and for downstream skill analysis. Recovering such motion solely from surgical videos is desirable, as it is compliant with current clinical workflows and instrumentation. We present Tracker of Anatomy and Tool (TAToo). TAToo jointly tracks the rigid 3D motion of the patient skull and surgical drill from stereo microscopic videos. TAToo estimates motion via an iterative optimization process in an end-to-end differentiable form. For robust tracking performance, TAToo adopts a probabilistic formulation and enforces geometric constraints on the object level. We validate TAToo on both simulation data, where ground truth motion is available, as well as on anthropomorphic phantom data, where optical tracking provides a strong baseline. We report sub-millimeter and millimeter inter-frame tracking accuracy for skull and drill, respectively, with rotation errors below [Formula: see text]. We further illustrate how TAToo may be used in a surgical navigation setting. We present TAToo, which simultaneously tracks the surgical tool and the patient anatomy in skull-base surgery. TAToo directly predicts the motion from surgical videos, without the need of any markers. Our results show that the performance of TAToo compares favorably to competing approaches. Future work will include fine-tuning of our depth network to reach a 1mm clinical accuracy goal desired for surgical applications in the skull base.

Progress in clinical application of computer-assisted orthopedic surgery

ABSTRACT With the rapid development of computer technology, new materials, 5G communication, artificial intelligence and robot technology, computer-assisted orthopaedic surgery (CAOS) technology has obtained an unprecedented opportunity for development, which has greatly promoted the personalized, accurate and minimally invasive process of orthopedic surgery. Compared with traditional orthopedic surgery, CAOS has significant advantages in implementing accurate surgery, shortening operation time, reducing patient trauma and reducing intraoperative X-ray radiation exposure. However, with the increasing medical needs of patients and the increasing medical costs, the technology of computer-assisted orthopedic surgery still needs to be improved. This paper mainly summarizes the current situation of clinical application of computer-assisted orthopedic surgery, focusing on following four aspects: broken bone splicing and restoration technology, 3D printing guide plate assisted orthopedic surgery, computer-assisted navigation in orthopedic surgery and orthopedic surgery robot technology. At the same time, the problems and difficulties existing in CAOS are discussed, and the author's own views on the future development of computer-assisted orthopedic surgery are put forward.