Intraoperative Planning Research Articles

National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection.

Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM. As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child's neurooncological and clinical outcome are essential.

Software-based method for automated intraoperative planning of Schoettle Point in surgical medial patellofemoral ligament reconstruction: A comparative validation study.

The aim of the study was to validate a software-based planning method for the Schoettle Point and to evaluate precision and time efficiency of its live overlay on the intraoperative X-ray. A software-based method was compared with surgeons' manual planning in an inter- and intrarater study. Subsequently, K-wire placement was performed with and without an overlay of the planning. The time used and the precision achieved were statistically compared. The average deviation between the surgeons (1.68mm; 2.26mm) was greater than the discrepancy between the surgeons and the software-based planning (1.30mm; 1.38mm). In the intrarater comparison, software-based planning provided consistent results. Live overlay showed a significantly lower positioning error (0.9±0.5mm) compared with that without overlay (3.0±1.4mm, p=0.000; 3.1±1.4mm, p=0.001). Live overlay did not achieve a significant time gain (p=0.393; p=0.678). The software-based planning and live overlay of the Schoettle Point improves surgical precision without negatively affecting time efficiency.

The Role of Virtual Surgical Planning in Surgery for Complex Craniosynostosis.

Virtual surgical planning (VSP) decreases reliance on intraoperative subjective assessment of aesthetic and functional outcomes in craniofacial surgery. Here, we describe our experience of using VSP for complex craniosynostosis surgery to inform preoperative decision making and optimize postoperative outcomes. Chart review was performed for children treated with craniosynostosis at our institution from 2015 to 2021. Eight VSP maneuvers were defined and assigned to each patient when applicable: (1) complex cranioplasty: combined autologous and synthetic; (2) autologous cranioplasty; (3) synthetic cranioplasty; (4) vector analysis and distractor placement; (5) complex osteotomies; (6) multilayered intraoperative plans; (7) volume analysis; and (8) communication with parents. Outcomes between VSP and non-VSP cohorts were compared. Of 166 total cases, 32 were considered complex, defined by multisutural craniosynostosis, syndromic craniosynostosis, or revision status. Of these complex cases, 20 underwent VSP and 12 did not. There was no difference in mean operative time between the VSP and non-VSP groups (541 versus 532 min, P = 0.82) or in unexpected return to operating room (10.5% versus 8.3%, P = 0.84). VSP was most often used to communicate the surgical plan with parents (90%) and plan complex osteotomies (85%). In this cohort, VSP was most often used to communicate the surgical plan with families and plan complex osteotomies. Our results indicate that VSP may improve intraoperative efficiency and safety for complex craniosynostosis surgery. This tool can be considered a useful adjunct to plan and guide intraoperative decisions in complex cases, reducing variability and guiding parental expectations.

From Augmented to Virtual Reality in Plastic Surgery: Blazing the Trail to a New Frontier.

Augmented reality (AR) and virtual reality (VR)-termed mixed reality-have shown promise in the care of operative patients. Currently, AR and VR have well-known applications for craniofacial surgery, specifically in preoperative planning. However, the application of AR/VR technology to other reconstructive challenges has not been widely adopted. Thus, the purpose of this investigation is to outline the current applications of AR and VR in the operative setting. The literature pertaining to the use of AR/VR technology in the operative setting was examined. Emphasis was placed on the use of mixed reality technology in surgical subspecialities, including plastic surgery, oral and maxillofacial surgery, colorectal surgery, neurosurgery, otolaryngology, neurosurgery, and orthopaedic surgery. Presently, mixed reality is widely used in the care of patients requiring complex reconstruction of the craniomaxillofacial skeleton for pre- and intraoperative planning. For upper extremity amputees, there is evidence that VR may be efficacious in the treatment of phantom limb pain. Furthermore, VR has untapped potential as a cost-effective tool for microsurgical education and for training residents on techniques in surgical and nonsurgical aesthetic treatment. There is utility for mixed reality in breast reconstruction for preoperative planning, mapping perforators, and decreasing operative time. VR has well- documented applications in the planning of deep inferior epigastric perforator flaps by creating three-dimensional immersive simulations based on a patient's preoperative computed tomography angiogram. The benefits of AR and VR are numerous for both patients and surgeons. VR has been shown to increase surgical precision and decrease operative time. Furthermore, it is effective for patient-specific rehearsal which uses the patient's exact anatomical data to rehearse the procedure before performing it on the actual patient. Taken together, AR/VR technology can improve patient outcomes, decrease operative times, and lower the burden of care on both patients and health care institutions.

Deformity, etiology, solution, sequence (DESS): Facial analysis in rhinoplasty

PurposeRhinoplasty is amongst the most challenging surgeries to perfect and can take decades. This process begins during residency; however, residents often have limited exposure to rhinoplasty during their training and lack a standardized method for systematically analyzing and formulating a surgical plan. The DESS (Deformity, Etiology, Solution, Sequence) is a novel educational format for residents that serves to increase their pre-operative comfort with the surgical evaluation and intraoperative planning for a rhinoplasty. Materials and methodsA qualitative study performed at a tertiary academic institution with an otolaryngology residency program evaluating three consecutive residency classes comprised of four residents per class. A 9-item questionnaire was distributed to measure change in resident comfort after utilizing the DESS during their facial plastics rotation. Questionnaire responses highlighted resident comfort with facial nasal analysis, identifying deformities, suggesting surgical maneuvers, and synthesizing a comprehensive surgical plan. ResultsTen of the twelve residents surveyed responded. Of those that responded, comfort in facial nasal analysis, identification of common nasal deformities, surgical planning, and development of an overall surgical plan were significantly improved after completion of the facial plastic rotation. These residents largely attributed their success to the systematic educational format, with an average score of 4.8/5.0 (SD 0.42). ConclusionWhile rhinoplasty is a challenging artform to master, systematic approaches to analysis and operative planning are vital for teaching and guiding residents. Through this novel methodology, residents display significant improvement in their comfort with facial nasal analysis and overall surgical preparation.

Graded Epidural Anaesthesia as a Sole Anaesthetic Technique for Lower Limb Surgeries in Patients with Low Ejection Fraction: A Case Series

In patients with a history of ischemic heart disease with low ejection fraction, it’s always a challenge for the Anaesthesiologist to make a decision on whether to administer General Anaesthesia (GA), central neuraxial blockade, or both. When the Left ventricular ejection fraction (LVEF) percentage reduces to less than 35%, it indicates the presence of severe systolic dysfunction. Both general anaesthesia and regional anaesthesia carry potential risks due to these patients' low cardiac output status. Hemodynamic fluctuations associated with anaesthesia can be detrimental in these patients. A clear intraoperative plan should be designed to manage the hemodynamics of these patients. Here we report two cases of ischemic heart disease with low ejection fraction posted for orthopedic surgeries. Graded epidural anaesthesia was used as a sole anaesthetic technique. The patients were hemodynamically stable in the intraoperative as well as postoperative period. Keywords: Ischemic heart disease, Low Left Ventricular Ejection Fraction, Graded Epidural Anaesthesia, Cemented modular hemiarthroplasty, PFNA2.

Robotic-assisted total knee arthroplasty improved component alignment in the coronal plane compared with navigation-assisted total knee arthroplasty: a comparative study.

The purpose of this study was to directly compare implant placement accuracy and postoperative limb alignment between robotic-assisted total knee arthroplasty and navigation-assisted total knee arthroplasty. This retrospective case-control study included a consecutive series of 182 knees (robotic-assisted group, n = 103 knees; navigation-assisted group, n = 79). An image-free handheld robotic system (NAVIO) or an image-free navigation system (Precision N) was used. Component and limb alignment were evaluated on three-dimensional computed tomography scans and full-length standing anterior-posterior radiographs. We compared the errors between the final intraoperative plan and the postoperative coronal and sagittal alignment of the components and the hip-knee-ankle angle between the two groups. The orientation of the femoral and tibial components in the coronal plane were more accurate in the robotic-assisted group than in the navigation-assisted group (p < 0.05). There was no significant difference in the orientation of the femoral and tibial component in the sagittal plane between the two groups. There were fewer outliers in the tibial coronal plane in the robotic-assisted group (p < 0.05). There was also no significant difference in the frequency of outlying values for coronal or sagittal alignment of the femoral component or sagittal alignment of the tibial component or the hip-knee-ankle angle between the two groups. Robotic-assisted total knee arthroplasty using a handheld image-free system improved component alignment in the coronal plane compared with total knee arthroplasty using an image-free navigation system. Robotic surgery helps surgeons to achieve personalised alignment that may result in better clinical outcomes.

Total Knee Arthroplasty in a Patient with Ipsilateral Painless Hip Arthrodesis: Technical Surgical Tips and a Novel Method for Intraoperative Navigation-Assisted Planning.

Total knee arthroplasty (TKA) in the setting of a previous ipsilateral hip fusion/arthrodesis is an uncommon and challenging procedure. There is little information available in the literature on the challenges and techniques available to perform TKA in these patients. For a traditional TKA procedure, the patient is placed in the supine position and various knee-positioning devices are used to allow for adequate knee and hip flexion, which is required for surgical exposure and tibia preparation. Ipsilateral hip arthrodesis presents two major challenges: (1) Hip flexion is crucial for adequate knee flexion while the patient is supine during the TKA procedure, and (2) the use of advanced technology, specifically computer navigation and robotic-assisted surgery techniques, is limited due to the inability to acquire the hip center of rotation during surgery, due to the lack of hip motion. Therefore, equipment and positioning must be adjusted by the surgeon to facilitate TKA in these patients. This article reports the case of a 72-year-old male patient with a long-standing, painless right hip arthrodesis, presenting with end-stage osteoarthritis of the right knee, leg-length discrepancy, and an 11.6° difference between the mechanical and anatomical axes of the femur. We describe the unique surgical planning as well as the surgical positioning options that allow for adequate knee flexion and proper surgical exposure. Furthermore, we describe a novel method of computer-assisted navigation for intra-operative planning and execution utilizing a reflected tibia as a template for the distal femoral cut.

Preclinical to clinical translation for intervertebral disc repair: Effects of species-specific scale, metabolism, and matrix synthesis rates on cell-based regeneration.

A significant hurdle for potential cell-based therapies is the subsequent survival and regenerative capacity of implanted cells. While many exciting developments have demonstrated promise preclinically, cell-based therapies for intervertebral disc (IVD) degeneration fail to translate equivalent clinical efficacy. This work aims to ascertain the clinical relevance of both a small and large animal model by experimentally investigating and comparing these animal models to human from the perspective of anatomical scale and their cellular metabolic and regenerative potential. First, this work experimentally investigated species-specific geometrical scale, native cell density, nutrient metabolism, and matrix synthesis rates for rat, goat, and human disc cells in a 3D microspheroid configuration. Second, these parameters were employed in silico to elucidate species-specific nutrient microenvironments and predict differences in temporal regeneration between animal models. This work presents in silico models which correlate favorably to preclinical literature in terms of the capabilities of animal regeneration and predict that compromised nutrition is not a significant challenge in small animal discs. On the contrary, it highlights a very fine clinical balance between an adequate cell dose for sufficient repair, through de novo matrix deposition, without exacerbating the human microenvironmental niche. Overall, this work aims to provide a path towards understanding the effect of cell injection number on the nutrient microenvironment and the "time to regeneration" between preclinical animal models and the large human IVD. While these findings help to explain failed translation of promising preclinical data and the limited results emerging from clinical trials at present, they also enable the research field and clinicians to manage expectations on cell-based regeneration. Ultimately, this work provides a platform to inform the design of clinical trials, and as computing power and software capabilities increase in the future, it is conceivable that generation of patient-specific models could be used for patient assessment, as well as pre- and intraoperative planning.

PE065 - Why do surgeons need to change their intraoperative plan? A multicentric analysis of conversions in 2459 robot-assisted partial nephrectomies

PE065 - Why do surgeons need to change their intraoperative plan? A multicentric analysis of conversions in 2459 robot-assisted partial nephrectomies

Preoperative CT-Guided Coil Localization of Lung Nodule Resection: A Single-Center Experience.

The increased use of computed tomography (CT) for lung cancer screening has led to an increase in the incidence of lung nodules. However, accurately localizing small or deep-seated nodules remains challenging and often requires image-guided techniques. CT-guided coil localization has emerged as a popular method for precise localization. A retrospective analysis was conducted on a cohort of patients who underwent CT-guided coil localization followed by surgical resection of lung nodules at the National University Hospital, Singapore, between 2015 and 2021. The study examined the rates of successful localization, procedural complications, and postoperative length of stay. Descriptive statistics were employed for data analysis. This retrospective study included 55 patients with pulmonary nodules, of whom 76.4% had a history of previous malignancy. A total of 58 nodules were successfully localized using coil placement and distributed across various lung lobes. The average dimensions of the nodules were 8.4 ± 3.2 mm × 10.1 ± 4.0 mm, with an average distance of 10.9 ± 9.0 mm from the pleura. Surgical resection of the coiled nodules resulted in an average resected volume of 91.1 ± 76.0 cm3 and a resection margin of 9.5 ± 7.3 mm. Failed localization occurred in only 3.6% of cases. Procedural complications were observed in 21.8% of patients, including hemothorax, persistent air leaks, pneumothoraces, pleural effusion, pneumonia, and atelectasis, all of which were appropriately managed. The average length of postoperative hospital stay was 6.7 ± 15.9 days. Preoperative CT-guided coil localization is a reliable and safe technique for accurately localizing lung nodules before surgical resection. The high success rate of this approach enables precise intraoperative planning. Despite procedural complications, their manageable nature and the absence of major adverse events highlight the safety of this technique. Incorporating CT-guided coil localization into routine clinical practice can significantly enhance surgical planning, improve patient outcomes, and optimize resource utilization.

Ultrasound elastography in neurooncology: Basic principles, applications, and illustrative cases

Abstract Intraoperative ultrasound as an adjunct for brain and spinal cord tumors has seen an uptick in interest over the last few decades owing to real-time imaging, ease of use, and refining of the technology involved. Ultrasound elastography is a relatively newer modality that estimates tissue stiffness, parenchyma–tumor interface, and possibly tissue histology. Paired with B-mode ultrasound, elastography has the potential to guide tumor resection better and intraoperative planning. In this study, we describe the fundamental principles and different types of elastography techniques. We summarize the current use and demonstrate the application of strain elastography in brain tumor resection using a few cases.

Assessment of jejunal interposition perfusion using indocyanine green

IntroductionJejunal interposition (JI) is an option for oesophageal replacement in children; ensuring good graft perfusion is essential. We report three cases where Indocyanine Green (ICG) with Near-Infrared Fluorescence (NIRF) was used to assess perfusion during graft selection, passage into the chest and anastomotic assessment. This extra assessment may reduce risk of anastomotic leak and/or stricture. MethodsWe describe the technique and salient features of all patients who have undergone ICG/NIRF-assisted JI in our centre. Patient demographics, indications for surgery, intra-operative plan, video of NIR perfusion assessment, complications and outcomes were reviewed. ResultsICG/NIRF was used in three patients (2M:1F) at a dose of 0.2 mg/kg. ICG/NIRF imaging helped select the jejunal graft and confirmed perfusion after division of segmental arteries. Perfusion was assessed before and after passing the graft through the diaphragmatic hiatus and before and after making the oesophago-jejunal anastomosis. Intrathoracic assessment at the end of the procedure confirmed good perfusion of mesentery and intrathoracic bowel. In two patients, the reassurance contributed to successful procedures. In the third patient, graft selection was satisfactory, but borderline perfusion on clinical assessment after passing the graft to the chest, confirmed by ICG/NIRF meant the graft was abandoned. ConclusionsICG/NIRF imaging was feasible and augmented our subjective assessment of graft perfusion, giving greater confidence during graft preparation, movement, and anastomosis. In addition, the imaging helped us abandon one graft. This series demonstrates the feasibility and benefit of ICG/NIR use in JI surgery. Further studies are required to optimise ICG use in this setting.

Specular Reflection Removal for 3D Reconstruction of Tissues using Endoscopy Videos.

Endoscopy is widely employed for diagnostic examination of the interior of organs and body cavities and numerous surgical interventions. Still, the inability to correlate individual 2D images with 3D organ morphology limits its applications, especially in intra-operative planning and navigation, disease physiology, cancer surveillance, etc. As a result, most endoscopy videos, which carry enormous data potential, are used only for real-time guidance and are discarded after collection. We present a complete method for the 3D reconstruction of inner organs that suggests image extraction techniques from endoscopic videos and a novel image pre-processing technique to reconstruct and visualize a 3D model of organs from an endoscopic video. We use advanced computer vision methods and do not require any modifications to the clinical-grade endoscopy hardware. We have also formalized an image acquisition protocol through experimentation with a calibrated test bed. We validate the accuracy and robustness of our reconstruction using a test bed with known ground truth. Our method can significantly contribute to endoscopy-based diagnostic and surgical procedures using comprehensive tissue and tumor 3D visualization.

V05-04 APPLICATIONS OF 3-DIMENSIONAL VIRTUAL REALITY MODELS IN UROLOGIC ROBOTIC SURGERY

You have accessJournal of UrologyCME1 Apr 2023V05-04 APPLICATIONS OF 3-DIMENSIONAL VIRTUAL REALITY MODELS IN UROLOGIC ROBOTIC SURGERY Michael Emmerling, Hung Jui Tan, Joseph Shirk, and Marc Bjurlin Michael EmmerlingMichael Emmerling More articles by this author , Hung Jui TanHung Jui Tan More articles by this author , Joseph ShirkJoseph Shirk More articles by this author , and Marc BjurlinMarc Bjurlin More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003263.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Virtual Realtiy (VR) technologies have developed increasing relevance and implementation in the field of medicine, and more specifically in the realm of surgical management for Urologic cancers. Certain VR technologies can develop three-dimensional (3D) digital models from standard computed tomography (CT) and magnetic resonance imaging (MRI) scans to facilitate surgical planning and intra-operative guidance. Use of 3D VR models has been linked to improved patient outcomes. Specifically, the use of 3D VR technology in robotic assisted laparoscopic partial nephrectomy has led to reduced operative times, shorter hospital stay, reduced clamp time, and minimized blood loss. In this video, we will highlight the impact of 3D VR technology on intra-operative planning for patients undergoing partial nephrectomy for renal masses. METHODS: In this video abstract, we explore the use of 3D VR technology in 5 patients undergoing robotic-assisted laparoscopic partial nephrectomy for renal masses. We review the CT findings and subsequently rendered 3D VR images to highlight the impact of VR on clinical decision making regarding partial versus radical nephrectomy, transperitoneal versus retroperitoneal approach, optimal vascular control mechanisms, selective versus global clamping, and depth of tumor resection. RESULTS: The use of 3D VR software impacted operative planning in each of patient undergoing robotic assisted laparoscopic surgery for a renal mass. Pre-operative and intra-operative use of 3D VR software allowed the surgeon to individualize the operative approach for each patient based on specific anatomic considerations that were highlighted or augmented with 3D VR technology. CONCLUSIONS: VR models applied to robotic partial nephrectomy appear to demonstrate improvement in clinical outcomes, surgical planning, and preoperative and intraoperative guidance. The technology is evolving, and cost remains a consideration. Future challenges will be to adopt artificial Intelligence and machine learning to account for tissue deformation, organ mobility, and anatomical changes during dissection. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e425 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Michael Emmerling More articles by this author Hung Jui Tan More articles by this author Joseph Shirk More articles by this author Marc Bjurlin More articles by this author Expand All Advertisement PDF downloadLoading ...

An Update of In Vivo Application of Artificial Intelligence and Robotics for Percutaneous Nephrolithotripsy: Results from a Systematic Review.

Kidney puncture is a key step in percutaneous nephrolithotomy (PCNL). Ultrasound/fluoroscopic-guided access to the collecting systems is commonly used in PCNL. Performing a puncture is often challenging in kidneys with congenital malformations or complex staghorn stones. We aim to perform a systematic review to examine data on in vivo applications, outcomes, and limitations of using artificial intelligence and robotics for access in PCNL. The literature search was performed on November 2, 2022, using Embase, PubMed, and Google Scholar. Twelve studies were included. 3D in PCNL is useful for image reconstruction but also in 3D printing with definite benefits seen in improving anatomical spatial understanding for preoperative and intraoperative planning. 3D model printing and virtual and mixed reality allow for an enhanced training experience and easier access which seems to translate into a shorter learning curve and better stone-free rate compared to standard puncture. Robotic access improves the accuracy of the puncture for ultrasound- and fluoroscopic-guided access in both supine and prone positions. The potential advantage robotics are using artificial intelligence to do remote access, reduced number of needle punctures, and less radiation exposure during renal access. Artificial intelligence, virtual and mixed reality, and robotics may play a key role in improving PCNL surgery by enhancing all aspects of a successful intervention from entry to exit. There is a gradual adoption of this newer technology into clinical practice but is yet limited to centers with access and the ability to afford this.

Intramedullary Spinal Cord Metastases from Breast Cancer: A Systematic Review.

Intramedullary spinal cord metastases (ISCM) are deemed extremely aggressive, as confirmed by the low life expectancy since the diagnosis. Up to 26.5% of total ISCM stem from breast cancer (BC), representing the second most frequent primary site after the lung. The increasing incidence of BC and the widespread use of MRI for the diagnosis could therefore lead to an earlier diagnosis and, therefore, to a progressively longer survival in patients affected by ISCM from BC. This systematic review is intended to provide an orientation through a management algorithm for the most appropriate therapeutic approach in these patients. The research strategy initially relied on title and abstract analysis. The article's full text was retrieved for further investigation if the title and abstract met the inclusion criteria. The extracted data included the following: authors, publication time, study design, patient characteristics, ISCM location, treatment modalities, time interval from initial cancer diagnosis to ISCM diagnosis, clinical outcomes, and survival time. This systematic search regarding ISCM from BC yielded 574 articles. After screening, a total of 44 studies were included in this systematic review. A total of 123 patients were evaluated. The mean patient age was 53.2 years with a standard deviation of 10.4 years. Female patients were 122. There was only one male patient. ISCM from BC have a better prognosis than lung metastases and, thanks to recent advances in diagnostic imaging and intraoperative planning and neuromonitoring, an early diagnosis and a prompt multidisciplinary treatment may be accomplished. Prospective studies to generate evidence-based data regarding the most appropriate treatment for ISCM are mandatory.

Personalized alignment™ for total knee arthroplasty using the ROSA® Knee and Persona® knee systems: Surgical technique.

Total knee arthroplasty (TKA) procedures are expected to increase up to 565% in the United States over the next 3 decades. TKAs were traditionally performed with neutral mechanical alignments that provided equal medial and lateral gaps in extension and flexion to reduce implant wear but were less successful at restoring native knee function and associated with high patient dissatisfaction. Kinematic alignment (KA) restores native anatomy and minimizes soft tissue release; however, KAs that recreate severe deformities and/or biomechanically inferior alignments result in significant increases in implant stress and risk of aseptic loosening. Restricted kinematic alignment (rKA) recreates pre-arthritic anatomy within a range of acceptable alignment boundaries, and improved patient clinical scores and faster recoveries have been reported with rKA techniques. Personalized Alignment™ is an evolution of rKA that relies heavily upon robotic assistance to reliably recreate patient anatomy, native soft tissue laxity, and accurate component placement to improve patients' clinical outcomes. The purpose of this surgical technique report is to describe the Personalized Alignment TKA method using the ROSA® Knee System and Persona® The Personalized Knee® implants. Herein we provide specific procedures for pre-operative planning, anatomical landmarking and evaluation, intra-operative planning and adjustment of resections and cuts, cut validation and soft tissue evaluation with robotic-assisted personalized TKA.

Improving tractography in brainstem cavernoma patients by distortion correction

IntroductionThe resection of brainstem cerebral cavernous malformations (CCM) harbors the risk of damaging the corticospinal tract (CST) and other major tracts. Hence, visualization of eloquent fiber tracts supports pre- and intraoperative planning. However, diffusion tensor imaging fiber tracking at brainstem level suffers from distortion due to field inhomogeneities and eddy currents by steep diffusion gradients. Research questionThis study aims to analyze the effect of distortion correction for CST tractography in brainstem CCM patients. Material and methods25 patients who underwent resection of brainstem CCM were enrolled, 24 suffered from hemorrhage. We performed an anatomically based tractography of the CST with a mean minimal fractional anisotropy of 0.22 ± 0.04 before and after cranial distortion correction (CDC). Accuracy was measured by anatomical plausibility and aberrant fibers. ResultsCDC led to a more precise CST tractography, further approximating its assumed anatomical localization in all cases. CDC resulted in a significantly more ventral location of the CST of 1.5 ± 0.6 mm (6.1 ± 2.7 mm before CDC vs. 4.6 ± 2.1 mm after CDC; p < .0001) as measured by the distance to the basilar artery and of 1.7 ± 0.6 mm (8.9 ± 2.7 mm vs. 7.2 ± 2.1 mm; p < .0001) in relation to the clivus. Aberrant fibers were reduced by CDC in 44% of cases. We found a mean difference in CST volume of 0.6 ± 0.8 ccm. We could not detect motor deficits after resection of irregular fibers. Discussion and conclusionCDC effectively corrects tractography for distortion at brainstem level, especially in patients suffering from brainstem CCM, further approximating its actual anatomical localization.

RETRACTED: Head-Mounted Augmented Reality in the Planning of Cerebrovascular Neurosurgical Procedures: A Single-Center Initial Experience

Augmented reality (AR) technology has played an increasing role in cerebrovascular neurosurgery over the last 2decades. Hence, we aim to evaluate the technical and educational value of head-mounted AR in cerebrovascular procedures. This is a single-center retrospective study of patients who underwent open surgery for cranial and spinal cerebrovascular lesions between April and August 2022. In all cases, the Medivis Surgical AR platform and HoloLens 2 were used for preoperative and intraoperative (preincision) planning. Surgical plan adjustment due to the use of head-mounted AR and subjective educational value of the tool were recorded. A total of 33 patients and 35 cerebrovascular neurosurgical procedures were analyzed. Procedures included 12 intracranial aneurysm clippings, 6 brain and 1 spinal arteriovenous malformation resections, 2 cranial dural arteriovenous fistula obliterations, 3 carotid endarterectomies, two extracranial-intracranial direct bypasses, two encephaloduroangiosynostosis for Moyamoya disease, 1 biopsy of the superficial temporal artery, 2 microvascular decompressions, 2 cavernoma resections, 1 combined intracranial aneurysm clipping and encephaloduroangiosynostosis for Moyamoya disease, and 1 percutaneous feeder catheterization for arteriovenous malformation embolization. Minor changes in the surgical plan were recorded in 16 of 35 procedures (45.7%). Subjective educational value was scored as "very helpful" for cranial, spinal arteriovenous malformations, and carotid endarterectomies; "helpful" for intracranial aneurysm, dural arteriovenous fistulas, direct bypass, encephaloduroangiosynostosis, and superficial temporal artery-biopsy; and "not helpful" for cavernoma resection and microvascular decompression. Head-mounted AR can be used in cerebrovascular neurosurgery as an adjunctive tool that might influence surgical strategy, enable 3-dimensional understanding of complex anatomy, and provide great educational value in selected cases.