Accuracy of robotic arm-assisted versus computed tomography-based navigation in total hip arthroplasty using the direct anterior approach: a retrospective study.

BACKGROUND: A robotic arm-assisted and a computed tomography (CT)- based navigation system have been reported to improve the accuracy of component positioning in total hip arthroplasty (THA). However, no study has compared robotic arm-assisted THA (rTHA) to CT-based navigated THA (nTHA) concerning accuracy of cup placement and acetabular fractures using the direct anterior approach (DAA). This study aimed to compare the accuracy of cup placement and the presence of intraoperative acetabular fractures between rTHA and nTHA using DAA in the supine position. METHODS: We retrospectively investigated 209 hips of 188 patients who underwent rTHA or nTHA using DAA (rTHA using the Mako system: 85 hips of 79 patients; nTHA: 124 hips of 109 patients). After propensity score matching for age and sex, each group consisted of 73 hips. We evaluated clinical and radiographic outcomes, comparing postoperative cup orientation and position, measured using a three-dimensional templating software, to preoperative CT planning. Additionally, we investigated the prevalence of occult acetabular fracture. RESULTS: Clinical outcomes were not significantly different between the groups at 1 year postoperatively. The mean absolute error of cup orientation was significantly smaller in the rTHA group than in nTHA (inclination: 1.4° ± 1.2° vs. 2.7° ± 2.2°, respectively; p = 0.0001, anteversion: 1.5° ± 1.3° vs. 2.2° ± 1.7°, respectively; p = 0.007). The cases within an absolute error of 5 degrees in both RI and RA were significantly higher in the rTHA (97.3%) than in nTHA group (82.2%) (p = 0.003). The absolute error of the cup position was not significantly different between the two groups. The prevalence of occult acetabular fracture did not differ significantly between the two groups (rTHA: n = 0 [0%] vs. nTHA: n = 1 [1.4%]). CONCLUSION: Cup placement using DAA in the supine position in rTHA was more accurate with fewer outliers compared to nTHA. Therefore, rTHA performed via DAA in a supine position would be useful for accurate cup placement.

Novel use of dynamic navigation for guiding a piezoelectric device during window osteotomy for maxillary sinus floor elevation in complex clinical scenarios.

In patients with severe atrophy of the posterior maxilla requiring lateral maxillary sinus floor elevation (MSFE), the window location and size are commonly designed according to the future implants and anatomical conditions. A window osteotomy becomes challenging when there is an extended edentulous space in the maxilla with no reference from the natural dentition, or when the surgical site involves anatomical variations, for example in the course of a large vessel or a sinus septum. Through preoperative planning and real-time visualization, the application of dynamic navigation allows an accurate location, optimal dimension, and customized shape during lateral window osteotomy. This article introduces a digital protocol for ensuring an accurate and safe window osteotomy for MSFE in complex clinical scenarios, by integrating dynamic navigation and a piezoelectric device.

Three-dimensional computer navigation in the reconstruction of complex unilateral orbital fractures: evaluation and review of applications.

BACKGROUND: The eyes are the central aesthetic unit of the face. Maxillofacial trauma can alter facial proportions and affect visual function with varying degrees of severity. Conventional approaches to reconstruction have numerous limitations, making the process challenging. The primary objective of this study was to evaluate the application of three-dimensional (3D) navigation in complex unilateral orbital reconstruction. METHODS: A prospective cohort study was conducted over 19 months (January 2020 to July 2021), with consecutive enrollment of 12 patients who met the inclusion criteria. Each patient was followed for a minimum period of 6 months. The principal investigator carried out a comparative analysis of several factors, including fracture morphology, orbital volume, globe projection, diplopia, facial morphic changes, lid retraction, and infraorbital nerve hypoesthesia. RESULTS: Nine patients had impure orbital fractures, while the remainder had pure fractures. The median orbital volume on the normal side (30.12 cm3; interquartile range [IQR], 28.45-30.64) was comparable to that of the reconstructed orbit (29.67 cm3; IQR, 27.92-31.52). Diplopia improved significantly (T(10) = 2.667, p = 0.02), although there was no statistically significant improvement in globe projection. Gross symmetry of facial landmarks was achieved, with comparable facial width-to-height ratio and palpebral fissure lengths. Two patients reported infraorbital hypoesthesia at presentation, which persisted at the 6-month follow-up. Additionally, five patients developed lower lid retraction (1-2 mm), and one experienced implant impingement at the infraorbital border. CONCLUSION: Our study provides level II evidence supporting the use of 3D navigation to improve surgical outcomes in complex orbital reconstruction.

3-Dimensional accuracy of navigation-guided bimaxillary orthognathic surgery: A systematic review and meta-analysis.

The transfer of a virtual orthognathic surgical plan to the patient still relies on the use of occlusal splints, which have limitations for vertical positioning of the maxilla. The use of real-time navigation has been proposed to enhance surgical accuracy. This systematic review (PROSPERO CRD42024497588) aimed to investigate if surgical navigation can improve the three-dimensional accuracy of orthognathic surgery. The inclusion criteria were orthognathic surgery, use of intra-operative navigation and quantitative assessment of surgical accuracy. The exclusion criteria were non-bimaxillary orthognathic surgeries, non-clinical studies, studies without post-operative 3D analysis and publications not in the English language. A search of PubMed, Embase and Cochrane Library generated 940 records, of which 12 were found relevant. Risk of bias was assessed done using the Joanna Briggs Institute Critical Appraisal Checklist Tool. Among the included studies, there were nine of observational character and three randomized control studies (RCTs). All studies demonstrated promising outcomes with reported good surgical accuracy within a 2 mm difference between the planned and post-surgical result. Meta-analysis of two RCTs was carried out and results were in favor of surgical navigation with a total odds ratio of 4.44 [2.11, 9.37] and an overall effect outcome of Z = 3.92 (p < 0.0001). Navigation was up to 0.60 mm more accurate than occlusal wafers only (p < 0.001). However, there were variations in the application of surgical navigation and methods of analysis, leading to a heterogenous data set. Future studies should focus on standardized protocols and analysis methods to further validate the use of surgical navigation in orthognathic surgery. Despite some limitations, surgical navigation shows potential as a valuable tool in improving the accuracy of orthognathic surgery.

Augmented Reality (AR) in Surgery in Low- and Middle-Income Countries (LMICs): A Scoping Review.

Surgical disparities persist in low- and middle-income countries (LMICs). Insufficient access to surgical care places a large burden on these regions, with high mortality rates for otherwise standard procedures performed in high-income countries (HICs). Augmented Reality (AR) and Virtual Reality (VR) now provide us with a platform to improve the delivery of surgical access and training to LMICs. The use of AR technologies to provide additional training to surgeons and residents globally can help bridge the gap and reduce health disparities in LMICs. The goal of this scoping review is to evaluate whether surgical trainees and surgeons from LMICs have access to or use AR software in their training or practice. A systematic search was conducted on seven databases. Inclusion criteria included populations in LMICs with access to AR-based training. Articles using VR software, or those conducted in HICs were excluded from the review. From the 428 records screened, 58 reports were assessed for eligibility, and of these, a total of six studies were included in the review. Five of the six studies used mentors from an HIC, including the United States (US) and the United Kingdom (UK), whereas one study had mentorship from another LMIC. Three surgical specialties were explored: neurosurgery, plastic surgery, and urology. Although the integration of AR in surgical training is promising, the six studies evaluated in this review emphasize that costs and connection issues are major challenges that can set back these technologies in the operating room. Despite these revelations, with certain improvements, AR training programs are promising as they can help to reduce the global disparity in surgical proficiency.

Accuracy of dynamic computer-assisted implant surgery in fully edentulous patients: An in vitro study.

OBJECTIVES: To compare miniscrew versus bone tracing registration methods on dental implant placement accuracy and time efficiency in edentulous jaws using a dynamic computer-assisted implant surgery (d-CAIS) system. METHODS: Twelve fully edentulous maxillary models were allocated into two groups: miniscrew tracing (MST) group, where registration was performed by tracing four miniscrews; and bone tracing (BT) group, where registration was conducted by tracing maxillary bone fiducial landmarks. Six implants were placed on each model using the X-Guide® d-CAIS system. Pre- and postoperative cone-beam computed tomography (CBCT) scans were superimposed to evaluate implant placement accuracy. The time required for registration and the overall surgery time were also recorded. RESULTS: Thirty-six implants were placed in each group. The MST group showed significantly lower mean angulation deviations (mean difference (MD): -3.33°; 95 % confidence interval (CI): -6.56 to -0.09); p = 0.044), 3D platform deviations (MD: -1.01 mm; 95 % CI: -1.74 to -0.29; p = 0.006), 2D platform deviations (MD: -0.97 mm; 95 % CI: -1.71 to -0.23; p = 0.010), and 3D apex deviations (MD: -1.18 mm; 95 % CI: -1.92 to -0.44; p = 0.002) versus the BT group. The overall surgery time was similar for both groups (MD: 6.10 min.; 95 % CI: -0.31 to 12.51; p = 0.06), though bone tracing required significantly more time compared with miniscrew registration (MD: 4.79 min.; 95 % CI: 2.96 to 6.62; p < 0.05). CONCLUSIONS: Registration with MST increases the accuracy of implant placement with a d-CAIS system in edentulous jaws compared with the BT method, and slightly reduces the overall surgery time. CLINICAL SIGNIFICANCE: Miniscrew tracing registration improves implant placement accuracy in comparison with bone tracing registration.

Syringosubarachnoid shunting with augmented reality navigation through a keyhole laminectomy of the upper thoracic spine: illustrative case.

BACKGROUND: A syringosubarachnoid (SS) shunt combined with keyhole hemilaminectomy is a beneficial procedure that can reduce the size of the skin incision and the risk of complications. However, ingenuity is needed to confirm the position of the syrinx during surgery. The authors present a case in which they treated syringomyelia in the upper thoracic spine using augmented reality (AR) to confirm syrinx formation, bone resection, and skin incision. OBSERVATIONS: Microscope-based AR was an appropriate and practical choice in this case. By placing the reference array at the Mayfield clamp, it was possible to use AR from the point of skin incision. Under AR navigation, an SS shunt tube can be placed in the short syrinx. LESSONS: AR navigation enables pinpoint SS shunt tube insertion with minimal skin incision and bone resection. It is particularly useful for upper thoracic and small syrinx lesions. https://thejns.org/doi/10.3171/CASE24130.

Vessel-based CTA-image to spatial anatomy registration using tracked catheter position data: preclinical evaluation of in vivo accuracy.

Electromagnetic tracking of endovascular instruments has the potential to substantially decrease radiation exposure of patients and personnel. In this study, we evaluated the in vivo accuracy of a vessel-based method to register preoperative computed tomography angiography (CTA) images to physical coordinates using an electromagnetically tracked guidewire. Centerlines of the aortoiliac arteries were extracted from preoperative CTA acquired from five swine. Intravascular positions were obtained from an electromagnetically tracked guidewire. An iterative-closest-point algorithm registered the position data to the preoperative image centerlines. To evaluate the registration accuracy, a guidewire was placed inside the superior mesenteric, left and right renal arteries under fluoroscopic guidance. Position data was acquired with electromagnetic tracking as the guidewire was pulled into the aorta. The resulting measured positions were compared to the corresponding ostia manually identified in the CTA images after applying the registration. The three-dimensional (3D) Euclidean distances were calculated between each corresponding ostial point, and the root mean square (RMS) was calculated for each registration. The median 3D RMS for all registrations was 4.82 mm, with an interquartile range of 3.53-6.14 mm. A vessel-based registration of CTA images to vascular anatomy is possible with acceptable accuracy and encourages further clinical testing. RELEVANCE STATEMENT: This study shows that the centerline algorithm can be used to register preoperative CTA images to vascular anatomy, with the potential to further reduce ionizing radiation exposure during vascular procedures. KEY POINTS: Preoperative images can be used to guide the procedure without ionizing intraoperative imaging. Preoperative imaging can be the only imaging modality used for guidance of vascular procedures. No need to use external fiducial markers to register/match images and spatial anatomy. Acceptable accuracy can be achieved for navigation in a preclinical setting.

The effect on the performance of a dynamic navigation system of superimposing a standard tessellation language (STL) file obtained with an intraoral scan on a cone beam computer tomograph (CBCT). An experimental in vitro study.

OBJECTIVES: To compare the accuracy and operative time of implant placement using a dynamic computer assisted implant surgery (dCAIS) system based on a cone beam computer tomography (CBCT) image, with and without superimposing a standard tessellation language (STL) file of an intraoral scan of the patient. METHODS: Ten identical resin models simulating an upper maxilla with posterior edentulism were assigned to two groups. In the CBCT+STL group, a CBCT file and an intraoral STL file were superimposed and used for registration; in the CBCT group, registration was performed using CBCT images. Six implants were placed in each model using the Navident® dynamic navigation system. Anatomy registration was performed by tracing fiducial points on the CBCT or STL image, depending on the group. Preoperative and postoperative CBCT images were overlaid to assess implant placement accuracy. RESULTS: Sixty implants were analyzed (30 implants in each group). 3D platform deviation was significantly lower (mean difference (MD): 0.17 mm; 95 % confidence interval (CI): 0.01 to 0.23; P = 0.039) in the CBCT+STL group (mean: 0.71 mm; standard deviation (SD): 0.29) than in the CBCT group (mean: 0.88 mm; SD: 0.39). The remaining accuracy outcome variables (angular deviation MD: -0.01; platform lateral deviation MD: 0.08 mm; apex global MD: 0.01 mm; apex depth MD: 0.33 mm) and surgery time (MD: 3.383 min.) were similar in both groups (p > 0.05). CONCLUSIONS: The introduction of an intraoral scan (STL) seems to reduce deviations slightly in dental implant placement with dCAIS systems. However, the clinical repercussion of this improvement is questionable. CLINICAL SIGNIFICANCE: Superimposing an intraoral scan on the CBCT image does not seem to increase the accuracy of dCAIS systems but can be useful when radiographic artifacts are present.

Recent Advances in Digital Technology in Implant Dentistry.

Digital technology has emerged as a transformative tool in dental implantation, profoundly enhancing accuracy and effectiveness across multiple facets, such as diagnosis, preoperative treatment planning, surgical procedures, and restoration delivery. The multiple integration of radiographic data and intraoral data, sometimes with facial scan data or electronic facebow through virtual planning software, enables comprehensive 3-dimensional visualization of the hard and soft tissue and the position of future restoration, resulting in heightened diagnostic precision. In virtual surgery design, the incorporation of both prosthetic arrangement and individual anatomical details enables the virtual execution of critical procedures (e.g., implant placement, extended applications, etc.) through analysis of cross-sectional images and the reconstruction of 3-dimensional surface models. After verification, the utilization of digital technology including templates, navigation, combined techniques, and implant robots achieved seamless transfer of the virtual treatment plan to the actual surgical sites, ultimately leading to enhanced surgical outcomes with highly improved accuracy. In restoration delivery, digital techniques for impression, shade matching, and prosthesis fabrication have advanced, enabling seamless digital data conversion and efficient communication among clinicians and technicians. Compared with clinical medicine, artificial intelligence (AI) technology in dental implantology primarily focuses on diagnosis and prediction. AI-supported preoperative planning and surgery remain in developmental phases, impeded by the complexity of clinical cases and ethical considerations, thereby constraining widespread adoption.

The influence of radiographic marker registration versus a markerless trace registration method on the implant placement accuracy achieved by dynamic computer-assisted implant surgery. An in-vitro study.

OBJECTIVES: This study aimed to compare the effect the radiographic marker registration (RMR) and markerless tracing registration (MTR) on implant placement accuracy using a dynamic computer-assisted implant surgery system (dCAIS). Additionally, this study aimed to assess the surgical time and whether the implant location influences the accuracy of the two registration methods. METHODS: 136 dental implants were randomly allocated to the RMR or MTR group and were placed with a dCAIS in resin models. Preoperative and postoperative Cone Beam Computer Tomograms (CBCT) were overlaid and implant placement accuracy was assessed. Descriptive and multivariate analysis of the data was performed. RESULTS: Significant differences (P < 0.001) were found for all accuracy variables except angular deviation (RMR:4.30° (SD:4.37°); MTR:3.89° (SD:3.32°)). The RMR had a mean 3D platform deviation of 1.53 mm (SD:0.98 mm) and mean apex 3D deviation of 1.63 mm (SD:1.05 mm) while the MTR had lower values (0.83 mm (SD:0.67 mm) and 1.07 mm (SD:0.86 mm), respectively). In the MTR group, implant placement in the anterior mandible was more accurate (p < 0.05). Additionally, MTR did not significantly increase the surgical time compared with RMR (P = 0.489). CONCLUSIONS: MTR seems to increase the accuracy of implant placement using dCAIS in comparison with the RMR method, without increasing the surgical time. The operated area seems to be relevant and might influence the implant deviations. CLINICAL SIGNIFICANCE: Considering the limitations of this in-vitro study, MTR seems to provide a higher accuracy in implant placement using dCAIS without increasing the surgical time. Furthermore, this method does not require radiographic markers and allows re-registration during surgery.

Retrospective study comparing the accuracies of handheld infrared stereo camera and augmented reality-based navigation systems for total hip arthroplasty.

BACKGROUND: The use of portable navigation systems (PNS) in total hip arthroplasty (THA) has become increasingly prevalent, with second-generation PNS (sPNS) demonstrating superior accuracy in the lateral decubitus position compared to first-generation PNS. However, few studies have compared different types of sPNS. This study retrospectively compares the accuracy and clinical outcomes of two different types of sPNS instruments in patients undergoing THA. METHODS: A total of 158 eligible patients who underwent THA at a single institution between 2019 and 2022 were enrolled in the study, including 89 who used an accelerometer-based PNS with handheld infrared stereo cameras in the Naviswiss group (group N) and 69 who used an augmented reality (AR)-based PNS in the AR-Hip group (group A). Accuracy error, navigation error, clinical outcomes, and preparation time were compared between the two groups. RESULTS: Accuracy errors for Inclination were comparable between group N (3.5° ± 3.0°) and group A (3.5° ± 3.1°) (p = 0.92). Accuracy errors for anteversion were comparable between group N (4.1° ± 3.1°) and group A (4.5° ± 4.0°) (p = 0.57). The navigation errors for inclination (group N: 2.9° ± 2.7°, group A: 3.0° ± 3.2°) and anteversion (group N: 4.3° ± 3.5°, group A: 4.3° ± 4.1°) were comparable between the groups (p = 0.86 and 0.94, respectively). The preparation time was shorter in group A than in group N (p = 0.036). There were no significant differences in operative time (p = 0.255), intraoperative blood loss (p = 0.387), or complications (p = 0.248) between the two groups. CONCLUSION: An Accelerometer-based PNS using handheld infrared stereo cameras and AR-based PNS provide similar accuracy during THA in the lateral decubitus position, with a mean error of 3°-4° for both inclination and anteversion, though the AR-based PNS required a shorter preparation time.

User Experience Evaluation of a Spinal Surgery Robot: Workload, Usability, and Satisfaction Study.

BACKGROUND: Robotic spine surgery has continued to evolve since its US Food and Drug Administration approval in 2004, with products now including real-time video guidance and navigation during surgery. As the market for robotic surgical devices evolves, it is important to consider usability factors. OBJECTIVE: The primary objective of this study was to determine the user experience of a surgical-assistive robotic device. The secondary objective was to evaluate workload, usability, the After-Scenario Questionnaire (ASQ), and the System Usability Scale (SUS). In addition, this study compares the workload, usability, and satisfaction survey of the device among different occupational groups using the device. METHODS: Doctors (n=15) and nurses (n=15), the intended users of the surgical assistant robot, participated in the usability evaluation. Participants performed essential scenarios for the surgical assistant robot and provided scenario-specific satisfaction (ASQ), workload (NASA Task Load Index), and usability (SUS) scores. RESULTS: Both doctors and nurses had task success rates of 85% or higher for each scenario. ASQ results showed that both doctors and nurses were least satisfied with ease of completing the task of registration (group 1: mean 4.73, SD 1.57 and group 2: mean 4.47, SD 1.8), amount of time it took (group 1: mean 4.47, SD 1.63 and group 2: mean 4.40, SD 2.09), and support information satisfaction (group 1: mean 5.13, SD 1.50 and group 2: mean 5.13, SD 1.89). All participants had low workloads, and the overall Task Load Index score had a P value of .77, which is greater than .05. The SUS results showed that the overall usability mean for doctors was 64.17 (SD 16.52) and the mean for nurses was 61.67 (SD 19.18), with a P value of .84, which is greater than .05, indicating no difference between the 2 groups. CONCLUSIONS: In this study, doctors and nurses evaluated the interaction of the device in a simulated environment, the operating room. By evaluating the use experience and usability of the device with real intended users, we can develop a more effective and convenient user interface.

Prosthetically driven robot-assisted implant surgery: turning a major failure into a simple case.

This case report presents a challenging case of catastrophic failure of a fixed partial denture involving fracture of the prosthesis as well as supporting implants and teeth. The use of robotics facilitated efficient and successful restoration of the patient's dentition. After extraction of 2 fractured teeth and 1 fractured implant, 2 new implants were placed with haptic guidance from robotics, which allowed for stable osteotomies and high initial implant stability quotients. Due to the patient's tremors and heavy occlusal forces, restoration was delayed to allow the surgical site to heal, and the patient received a provisional partial denture. With subsequent placement of the final restoration, the treatment was fully completed in 4.5 months and required only a single surgical procedure. The use of haptic robotics in this case allowed for accurate planning, spacing, and placement of screw-retained implants with an optimal arch, leading to the best long-term outcome for the patient.

[Navigation and robotics-current status and future implications]. / Navigation und Robotik ­ status präsens und zukünftige Implikationen.

INTRODUCTION: Both navigation systems and robotics enable greater precision in the implantation of an artificial knee joint. However, they do not improve clinical outcomes. We hypothesized that although implantation of a total knee arthroplasty results in reconstruction of the alignment in the coronal plane, the variable rotational tibial and variable translational femoral and tibial component positioning lead to a change in the remaining alignment parameters of the lower extremity. However, these parameters could be determined using a navigation system or robot and could represent future implications for these systems. METHODS: The kinematics and the position between femur and tibia before and after implantation of a total knee arthroplasty were determined using a navigation system in nine healthy knee joints of Thiel-fixed whole-body cadavers. RESULTS: After arthroplasty, there was no change in the natural coronal alignment. In extension and the early degrees of flexion, the rotational position of the femur relative to the tibia was altered. This also led to a change in the positioning of the medial and lateral epicondyle in relation to the tibia; while both epicondyles were positioned more laterally in relation to the tibia after arthroplasty, the lateral epicondyle was significantly more lateral in relation to the tibia up to 20° of flexion. DISCUSSION: Following arthroplasty of a knee joint using the established technique, a good reconstruction of the coronal alignment was achieved with simultaneous changes in the alignment in both the rotational and translational directions between the femur and tibia. Using navigation as well as robotics, we would be able to quantify all alignment parameters and could achieve an alignment of the components or a reconstruction of the overall alignment in all six degrees of freedom. We might also be able to achieve a clinical advantage or increase the service life even further.

Dynamic navigation-assisted bone ring technique for partially edentulous patients with severe vertical ridge defects.

The autogenous bone ring technique is among the approaches for vertical alveolar ridge augmentation, and this technique can enable simultaneous implantation. However, the outcomes can be compromised due to donor site morbidity, shifting of the bone ring graft positioning, and inaccurate implant placement. In recent decades, dynamic navigation systems have been introduced into the field of implantology, allowing the accuracy of outcomes to be improved. This Technical Note describes the use of dynamic navigation to guide bone ring surgery, which is expected to enable more precise and predictable bone augmentation and implantation procedures, reduce the risk of injuries to the adjacent anatomical structures, and achieve better treatment outcomes.

O uso do planejamento virtual na cirurgia ortognática / The use of virtual planning in orthognathic surgery

Introdução: A cirurgia ortognática envolve manipulação da arquitetura óssea facial, através de osteotomias, para restaurar a forma e a função, corrigindo a má oclusão, as desproporções maxilomandibulares e assimetrias faciais. O planejamento virtual em cirurgia ortognática é realizado com ajuda de softwares que utilizam as medidas reais do esqueleto craniofacial e registros da oclusão do paciente, através de uma análise 3D. Método: Foram avaliados 18 pacientes com deformidades dentofaciais, de acordo com a classificação de Angle submetidos a cirurgia ortognática com o uso do planejamento virtual, entre 2018 e 2019. Os critérios de inclusão foram pacientes entre 16 e 60 anos com desproporções maxilo-mandibulares nas quais o tratamento ortodôntico isolado não era suficiente. Os critérios de exclusão foram a presença de lesões císticas ou tumorais nos maxilares e comorbidades clínicas que contraindicavam a cirurgia. O planejamento virtual foi realizado em todos os pacientes, utilizando o software Dolphin® Imaging 11 e os guias cirúrgicos confeccionados em impressora 3D. Resultados: O guia cirúrgico intermediário apresentou adaptação perfeita nas faces oclusais promovendo grande estabilidade para o reposicionamento e fixação da maxila na oclusão intermediária. Os 18 pacientes operados responderam como "totalmente satisfeitos" em relação ao resultado estético-funcional nessa série estudada. Foi encontrada uma semelhança muito grande da posição do esqueleto maxilofacial no planejamento virtual préoperatório e o obtido no pós-operatório, através da avaliação das telerradiografias. Conclusão: O planejamento virtual em cirurgia craniomaxilofacial possui inúmeras vantagens, como diminuição do tempo laboratorial pré-operatório, maior precisão na confecção dos guias cirúrgicos e melhor reprodutibilidade dos resultados simulados.

Introduction: Orthognathic surgery involves the manipulation of facial bone architecture through osteotomies to restore form and function, correcting malocclusion, maxillomandibular disproportions, and facial asymmetries. Virtual planning in orthognathic surgery is carried out with the help of software that uses real measurements of the craniofacial skeleton and records of the patient's occlusion through 3D analysis. Method: 18 patients with dentofacial deformities were evaluated, according to Angle's classification, who underwent orthognathic surgery using virtual planning between 2018 and 2019. The inclusion criteria were patients between 16 and 60 years old with maxylo-mandibular disproportions in which orthodontic treatment alone was not sufficient. Exclusion criteria were the presence of cystic or tumoral lesions in the jaw and clinical comorbidities that contraindicated surgery. Virtual planning was carried out on all patients, using Dolphin® Imaging 11 software and surgical guides made with a 3D printer. Results: The intermediate surgical guide presented perfect adaptation on the occlusal surfaces, promoting great stability for the repositioning and fixation of the maxilla in intermediate occlusion. The 18 operated patients responded as "completely satisfied" in relation to the aesthetic-functional result in this series studied. A very great similarity was found between the position of the maxillofacial skeleton in the preoperative virtual planning and that obtained post-operatively through the evaluation of teleradiography. Conclusion: Virtual planning in craniomaxillofacial surgery has numerous advantages, such as reduced pre-operative laboratory time, greater precision in the creation of surgical guides, and better reproducibility of simulated results.

Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques. MATERIALS AND METHODS: A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles. RESULTS: After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used. CONCLUSION: Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

An updated meta-analysis comparing complications, functional, clinically relevant and radiological outcomes of accelerometer based portable navigation and conventional technique of total knee arthroplasty.

Introduction: Since previous studies, including small-scale meta-analyses comparing accelerometer-based portable navigation (APN-TKA) and conventional techniqueof total knee arthroplasty (CONV-TKA), have reported divergent results, there is a need for an updated meta-analysis to compare complications, functional outcomes, clinically relevant outcomes and radiographic alignment of components. Methods: This meta-analysis was conducted as per PRISMA guidelines. Randomised controlled trials, and non-randomised comparative cohort studies in English language on primary TKA were included. The complications compared were Deep Vein Thrombosis (DVT), Pulmonary Embolism (PE), infection, manipulation under anaesthesia (MUA) for postoperative knee stiffness, re-operation and mortality. The functional outcomes compared were the Knee Society Knee Score, Knee Society Score function, Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score and Western Ontario and McMaster Universities Arthritis Index. The evaluated clinically relevant outcomes were surgical time, blood loss, drop in haematocrit, tourniquet time, postoperative knee flexion and complications). The number of radiological outliers; as well as the absolute values of the alignment of the overall prosthesis, femoral and tibial components in both coronal and sagittal planes, was assessed. Results: Twenty-five studies were included. Both the groups were comparable in terms of preoperative demographic features. There was no difference in complications and functional outcomes. Operation time was longer in APN-TKA (p < 0.00001) but there was no difference in rest of the clinically relevant outcomes. Restoration of the lower limb mechanical axis (p = 0.003) and coronal femoral alignment angle (p = 0.0002) was better with APN. APN also significantly reduced the risk of the odds of outliers of lower limb mechanical axis (p < 0.0001), coronal femoral alignment (p = 0.03), coronal tibial alignment (p < 0.0001) and sagittal tibial alignment (p = 0.0001). Conclusion: The improvement in the accuracy of implantation by the use of APN-TKA, as determined by the overall alignments of prosthesis, or femoral and tibial components, does not necessarily translate into lesser complications and better functional and clinical outcomes. Level of evidence: Therapeutic study, Level II.

Safe and time-saving treatment method for acute cerebellar infarction: Navigation-guided burr-hole aspiration - 6-years single center experience.

OBJECTIVE: While patients with medically intractable acute cerebellar infarction typically undergo suboccipital craniectomy and removal of the infarcted tissue, this procedure is associated with long operating times and postoperative complications. This study aimed to investigate the effectiveness of minimally invasive navigationguided burr hole aspiration surgery for the treatment of acute cerebellar infarction. METHODS: Between January 2015 and December 2021, 14 patients with acute cerebellar infarction, who underwent navigation-guided burr hole aspiration surgery, were enrolled in this study. RESULTS: The preoperative mean Glasgow Coma Scale (GCS) score was 12.7, and the postoperative mean GCS score was 14.3. The mean infarction volume was 34.3 cc at admission and 23.5 cc immediately following surgery. Seven days after surgery, the mean infarction volume was 15.6 cc. There were no surgery-related complications during the 6-month follow-up period and no evidence of clinical deterioration. The mean operation time from skin incision to catheter insertion was 28 min, with approximately an additional 13 min for extra-ventricular drainage. The mean Glasgow Outcome Scale score after 6 months was 4.8. CONCLUSIONS: Navigation-guided burr hole aspiration surgery is less time-consuming and invasive than conventional craniectomy, and is a safe and effective treatment option for acute cerebellar infarction in selected cases, with no surgery-related complication.