Preoperative Planning Research Articles

Semi-Automated Virtual Endoscopy of the Frontal Recess.

Virtual endoscopy (VE) is the computer-based reprocessing of diagnostic imaging to simulate endoscopy of an anatomic region of interest. VE of the Frontal Sinus Outflow Tract (FSOT) may assist surgical planning and education. VE was performed on 16 normal sinus computed tomography (CT) scans for a total of 32 sides using the "path-to-target" tool on the TruDi surgical navigation system (ver. 2.3; Acclarent, Irving, CA, USA). To aid orientation during VE, planning points were placed on the middle turbinate, ethmoidal bulla, and skull base. The VE representation of anatomy and FSOT accuracy was manually confirmed by reviewing the corresponding orthogonal CT images and comparing them to the computed pathway. Of the 32 sides, the software successfully calculated the FSOT in 22 sides (69%). Of those 22 sides, the calculated FSOT, depicted in the VE sequences accurately represented the FSOT. Among sides with an accurately calculated FSOT, the VE sequences depicted a "fly-through" from a starting point in the middle meatus around various frontal recess cells to the end point in the frontal sinus. This pilot study demonstrates that software-generated VE of the FSOT is indeed feasible but requires confirmation by the surgeon for accuracy. Instances in which the software did not achieve its objective may drive further refinements of the protocol. VE of the FSOT should be explored as a tool for preoperative planning and surgical education.

Relationship between peroneus longus tendon graft thickness and anthropometric variables: a radiographic study using ultrasonography

BackgroundThis study aimed to evaluate the predictive value of anthropometric measurements for two-stranded peroneus longus tendon (PLT) graft thickness using ultrasonographyMaterials and methodsA prospective study was conducted on 204 healthy volunteers (102 males and 102 females) aged 18–40 years. Anthropometric measurements were recorded, including height, weight, body mass index (BMI), fibular length, calf circumference, and ankle circumference. The Tegner Activity Scale (TAS) was used to assess activity levels. PLT cross-sectional area (CSA) was measured using ultrasonography. Two-stranded PLT graft thickness was calculated using the previously reported formula by Luo et al. A thickness of less than 8 mm of PLT graft was accepted as an insufficient autograft for anterior cruciate ligament reconstruction (ACLR). Correlation and regression analyses were performed to identify predictors of two-stranded PLT graft thickness. Receiver operating characteristic (ROC) analysis was performed to establish the best threshold values.ResultsMales had a significantly greater PLT CSA (0.17 ± 0.03 cm2) and predicted two-stranded PLT graft thickness (8.1 ± 0.6 mm) compared with females (0.15 ± 0.03 cm2 and 7.5 ± 0.6 mm, respectively; p < 0.001 for both). Correlation analysis revealed that two-stranded PLT graft thickness positively correlated with height, weight, BMI, fibular length, calf circumference, ankle circumference, and Tegner Activity Scale in both genders, with stronger correlations observed in females. The logistic regression model identified height and calf circumference as significant predictors of sufficient two-stranded PLT graft thickness (≥ 8 mm) in males, while calf circumference and the TAS were significant predictors in females. ROC analysis demonstrated that calf circumference and the TAS had acceptable discriminatory abilities in females, with 36.25 cm and ≥ 4 cutoff points, respectively. However, no anthropometric variables in males exhibited strong discriminatory abilities for predicting two-stranded PLT graft thicknessConclusionsCalf circumference and the TAS are significant predictors for two-stranded PLT autograft thickness in females. However, no anthropometric variables in males could be used strongly for prediction. These anthropometric measurements can assist in preoperative planning and decision-making, potentially improving ACLR outcomes by ensuring adequate graft thickness in females.Level of evidence: Level II prospective study

Chronic ankle instability: a cadaveric anatomical and 3D high-resolution MRI study for surgical reconstruction procedures

ObjectivesTo quantitatively investigate the anatomy of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) for surgical reconstruction procedures in chronic ankle instability (CAI).Methods3D MRI was performed on five fresh-frozen cadaveric ankles using six different spatial resolutions (0.3 × 0.3 × 0.3 mm3, 0.45 × 0.45 × 0.45 mm3, 0.6 × 0.6 × 0.6 mm3, 0.75 × 0.75 × 0.75 mm3, 0.9 × 0.9 × 0.9 mm3, 1.05 × 1.05 × 1.05 mm3). After comparing the MRI results with cadaver dissection, a resolution of 0.45 × 0.45 × 0.45 mm³ was selected for bilateral ankles MRI on 24 volunteers. Classification of the ATFL and four distances of surgically relevant bony landmarkers were analyzed (distance 1 and 3, the fibular origin of the ATFL and CFL to the tip of fibula, respectively; distance 2, the talar insertion of the ATFL to the bare zone of talus; distance 4, the calcaneal insertion of the CFL to the peroneal tubercle).ResultsIn subjective evaluation, the interobserver ICC was 0.95 (95% confidence interval (CI): 0.94–0.97) between two readers. The spatial resolution of 0.3 × 0.3 × 0.3 mm3 and 0.45 × 0.45 × 0.45 mm3 received highest subjective score on average and demonstrated highest consistency with autopsy measurements in objective evaluation. Measurements on the 48 volunteer ankles, distance 1 in type I and II were 12.65 ± 2.08 mm, 13.43 ± 2.06 mm (superior-banded in Type II) and 7.69 ± 2.56 mm (inferior-banded in Type II) (means ± SD), respectively. Distance 2 in type I and II were 10.90 ± 2.24 mm, 11.07 ± 2.66 mm (superior-banded in Type II), and 18.44 ± 3.28 mm (inferior-banded in Type II), respectively. Distance 3 and 4 were 4.71 ± 1.04 mm and 14.35 ± 2.22 mm, respectively.ConclusionWe demonstrated the feasibility of quantifying the distances between bony landmarkers for surgical reconstruction surgery in CAI using high-resolution 3D MRI.Critical relevance statementHigh-resolution 3D MRI examination may have a guiding effect on the preoperative evaluation of chronic ankle instability patients.Key PointsSpatial resolutions of 0.3 × 0.3 × 0.3 mm3 and 0.45 × 0.45 × 0.45 mm3 demonstrated highest consistency with autopsy measurements.The spatial resolution of 0.45 × 0.45 × 0.45 mm3 was conformed more to clinical needs.3D MRI can assist surgeons in developing preoperative plans for chronic ankle instability.Graphical

Apple Vision Pro and Its Implications in Mohs Micrographic Surgery: A Narrative Review.

Mohs micrographic surgery (MMS) is a precise and effective technique for treating skin cancers, necessitating high accuracy and real-time decision-making to ensure complete tumor removal while preserving healthy tissue. The introduction of the Apple Vision Pro (AVP), an advanced mixed-reality headset, presents a potential technological advancement in surgical practice. The present investigation explores the integration of AVP into Mohs surgery, focusing on its potential to enhance preoperative planning, intraoperative guidance, and postoperative analysis. The AVP's high-resolution displays, advanced eye-tracking technology, and real-time data overlay capabilities may assist in meticulous surgical planning and execution. In the preoperative phase, AVP enables the creation and manipulation of detailed 3D models, providing comprehensive visualizations of tumor margins and critical structures. During surgery, AVP's real-time data overlay aids in precise tumor excision and spatial orientation, reducing errors and improving outcomes. Postoperatively, the AVP facilitates detailed procedural reviews and serves as a robust educational tool for surgical trainees. Despite its promising applications, challenges such as real-time resolution limitations, potential eye strain from prolonged use, and high costs must be addressed for widespread clinical adoption. This review highlights the transformative potential of AVP in Mohs surgery and underscores the need for further research to optimize integration and maximize benefits in dermatological procedures.

Factors associated with rod fracture following surgery for adult spinal deformity: a single-center retrospective study.

Adult spinal deformity (ASD) has a significant impact on trunk balance and quality of life in the elderly. Postoperative rod fractures pose significant challenges, but the mechanisms of their occurrence are underexplored compared to other complications such as proximal junctional kyphosis. This study investigated factors associated with rod fracture in patients with ASD. A retrospective single-center study analyzed 110 adult patients who underwent spinal deformity correction between 2012 and 2020. Comparative analysis and univariate and multivariate Cox regression analyses were employed to identify factors associated with rod fracture. In this study, rod fracture occurred in 14.5% of patients. The rod fracture group exhibited a larger change in lumbar lordosis (LL), a higher proportion of patients with pre-operatively existing (pre-existing) vertebral fractures, and a greater percentage of patients with a rod diameter of 6mm or less compared to the non-rod fracture group. Univariate Cox regression analysis revealed that rod fracture was associated with pre-existing vertebral fracture, LL change, preoperative sagittal vertical axis, and preoperative pelvic tilt. Multivariate Cox regression analysis identified pre-existing vertebral fractures and the amount of LL change as independent factors associated with rod fractures. Pre-existing vertebral fractures and the magnitude of lumbar lordosis correction are independent risk factors for rod fracture following ASD surgery. Surgeons should consider these factors during preoperative planning to reduce the risk of postoperative rod fracture. IV.

A 3D-Planned Inward Fragmentation Technique for the Removal of Impacted Mandibular Third Molars: A Case Series.

Background/Objectives: The extraction of impacted mandibular third molars (M3Ms) carries significant risks, especially regarding the inferior alveolar nerve (IAN). This study aimed to evaluate the effectiveness of a 3D-planned inward fragmentation technique (3Dp-IFT) to improve surgical outcomes, reduce complications, and preserve bone structure in cases involving complex M3M impactions. Methods: Twenty-three patients aged between 18 and 36 years requiring M3M removal were included. Preoperative planning involved the use of cone-beam computed tomography (CBCT) for precise localization of the furcation area, followed by the creation of a 3D navigation template using PlastyCAD software version 1.7. The surgical procedure was performed under local anesthesia, with meticulous endoscopic assistance to ensure accurate access and minimize trauma. Postoperative outcomes, such as bone loss, pain, swelling, and mouth opening range, were carefully measured. The data were systematically organized and analyzed descriptively using Microsoft Excel. Results: No disturbances to the IAN or lingual nerve were observed. The mean buccal bone loss was 2.2 mm, with a standard deviation of 1.2 mm. Postoperative pain and swelling were generally low, with significant reductions within the first week. The use of the 3D navigation template significantly improved surgical access, enhancing safety and minimizing complications. Conclusions: The 3Dp-IFT technique represents a significant advancement in the minimally invasive removal of M3M by allowing precise access to critical anatomical areas while minimizing bone loss and postoperative complications. This approach is particularly beneficial for complex cases involving M3M near the IAN, thereby improving surgical safety and patient outcomes.

Surgeon perspectives on a virtual reality platform for preoperative planning in complex bone sarcomas

Background and objectivesTreatment of primary bone and soft tissue sarcomas typically includes complete surgical resection with or without adjunctive modalities. Despite best efforts, for the most challenging clinical scenarios such as axial or pelvic sarcoma, five-year survival rates are reported to be between 27 and 40 %. Since quality of resection is a key determinant of oncologic outcomes, it is critical to preoperatively plan the surgical approach to improve resection accuracy, ensure sufficient surgical margins, and reduce the risk of local or metastatic recurrence. The computer conversion of 2-dimensional (2D) computerized tomography (CT) and magnetic resonance imaging (MRI) to a three-dimensional (3D) virtual reality (VR) avatar image may allow improved preoperative estimation of tumor size, location, adjacent anatomy, and spatial understanding of the tumor without relying on surgeon experience, memory, and imagination. The purpose of this study is to investigate the utility of a virtual reality platform in preoperative planning and surgical approach in a retrospective cohort of pelvic bone sarcoma cases. MethodsThe histopathology database at our institution was queried for all historical cases of bone and soft tissue sarcoma with surgical resection failure, defined as positive gross or microscopic margins. Four cases of pelvic bone sarcoma were chosen for retrospective review by fellowship-trained orthopedic tumor specialists. For each case, participants first studied conventional 2D preoperative CT images and answered a questionnaire pertaining to objective case parameters. Participants then interacted with case-specific 3D models while wearing a VR headset and answered the same questionnaire. The VR ‘avatar’ was created with custom-developed software. After using both modalities, participants completed a Likert-scale survey aiming to evaluate the VR technology's subjective impact on understanding tumor environment, surgical plan confidence, and its ability to improve communication with colleagues and patients. Four attending orthopedic oncologists, one orthopedic oncology fellow, and one senior orthopedic oncology resident participated in the study. ResultsFour cases of failed resection were evaluated by a group of both attending surgeons and a group of trainees composed of both residents and fellows. Tumor borders were clearly delineated in 0 % and 66.6 % cases when evaluating with conventional 2D imaging and VR, respectively. Participants changed adjacent structure involvement grade 22.2 % of the time after assessing involvement grade on the VR technology, with adjacent ligamentous structure grading changed most frequently in 55.5 % of cases. Users reported they would change the surgical approach or margins 44.4 % of the time after reviewing with VR technology. Initial 6 plane resection plans were changed in every user case. Subjective responses indicated that surgeons expressed more confidence in their approach, confidence with obtaining negative margins, and provided more detail regarding structures to be resected in specific planes. ConclusionPelvic tumors present unique surgical challenges due to complex 3D anatomy, the proximity of vital structures, consistency of the tumor, and the need to alter patient position during resection procedures. Using examples of failed pelvic bone sarcoma resections, our study found that VR imaging increased understanding of the tumor environment, characteristics, and ability to communicate with patients and colleagues.

Isolated aseptic loosening in total knee arthroplasty: a comprehensive 10-year review of partial vs. total component revisions

BackgroundIn total knee arthroplasty (TKA), isolated aseptic loosening (IAL) requires the replacement of prosthetic components, with ongoing debate regarding the effectiveness of partial component revision (PCR) compared to total component revision (TCR). This study aims to compare implant survival and surgical outcomes between PCR and TCR in the context of IAL.MethodsThis retrospective study analyzed data from 285 patients who underwent revision TKA for IAL between January 2000 and December 2013. After applying exclusion criteria, 112 patients were included in the analysis—60 undergoing TCR and 52 undergoing PCR.ResultsPCR was associated with shorter operative times and hospital stays compared to TCR, alongside significant differences in the choice of revision prostheses. Although the prosthesis failure rates were comparable between the groups (13.6% for TCR and 18.33% for PCR), significant risk factors for failure were identified, including a canal filling ratio (CFR) below 0.8 and a discrepancy over 0.2 between CFR views. However, no significant differences in overall survivorship were observed between the groups.ConclusionsBoth PCR and TCR provide similar survival rates and clinical outcomes for managing IAL in TKA. PCR provides advantages in terms of surgical efficiency and patient recovery, while reducing the need for more constrained prosthetic solutions. The study identifies CFR as a critical predictor of prosthesis failure, highlighting the importance of detailed preoperative planning and implant selection. These findings contribute valuable insights for improving revision strategies in IAL, enhancing surgical outcomes in TKA.Level of evidenceIII.

CT-Based Evaluation of Volumetric Posterior Pelvic Bone Density with Implications for the Percutaneous Screw Fixation of the Sacroiliac Joint.

Background: Operative treatment of fragility fractures of the pelvis has become a gold standard. Preoperative planning, including the assessment of the pathway for iliosacral screws, is crucial. The anchorage of the screw depends on the bone quality. Some recent studies have concentrated on assessing bone mineral density (BMD) with the use of Hounsfield unit (HU) values obtained from CT scans. The aim of the present study is to determine the best sacral levels of S1-S3 on the pathway of iliosacral screws for sacroiliac joint fixation. Methods: Patients admitted to the Independent Public Healthcare Center in Rypin between 1 of September and 1 of December in 2023, who had CT scans of the pelvis performed on them for different reasons, were included in this study. In total, 103 patients-56 men and 47 women-were enrolled in the study and consecutively separated into two groups of different ages: 18-60 years old (group A) and above 60 years old (group B). The volumetric bone density expressed in HU values was measured with sacral levels of S1, S2 and S3. Apart from the bodies of sacral vertebrae S1-S3, our measurements involved the ala of the ilium in the vicinity of the sacroiliac joint and the wing of the sacrum. All the measurements were performed on the pathway of presumptive iliosacral screws to stabilize the sacroiliac joint. Results: In group A (58 patients) the highest bone density in sacral bodies was found in S1 that gradually decreased to S3, while the opposite tendency was demonstrated in the ala of ilium. The HU values in the wing of the sacrum did not display statistical significance. In group B (45 patients), the highest bone density was also found in the sacral body S1 that decreased toward S3 but in the ala of ilium, the highest bone density was found with level S1 and lowest with level S2. In both groups, the highest bone density referred to the wing of the sacrum. Conclusion: While the perfect construct for posterior pelvic ring fixation remains unclear, our findings may imply that sacroiliac joint screws inserted into the wing of the sacrum of greater bone density could provide much more successful fixation in comparison to those anchored in the body of sacral vertebra of lesser bone density.

Application of 3D-Slicer Software in the Treatment of Gliomas.

To explore the application of 3D-Slicer multimodal image fusion technology in the surgical treatment of gliomas. A retrospective analysis of clinical data from 48 cases of intracranial gliomas treated with 3D-Slicer multimodal image fusion technology from September 2021 to February 2023. Preoperative cranial CT, MRI, TOF-MRA, DTI, and MRV sequence examinations were completed. DICOM format medical imaging data were processed using the 3D-Slicer software. Multimodal fusion and 3-dimensional reconstruction of the tumor and surrounding structures were conducted to clarify the relationship between the tumor and surrounding structures. The surgery path was simulated through 3D virtual visualization images, enabling precise preoperative planning and assisting in surgical treatment. Out of 48 patients, complete tumor resection was achieved in 45 cases. One case encountered severe postoperative cerebral edema, no infections were reported, 1 patient had slightly reduced muscle strength after surgery compared with before, and no cases of severe neurological function damage or surgical death were recorded. 3D-Slicer multimodal image fusion technology can assist in detailed preoperative planning for the surgical treatment of intracranial glioma, reducing surgical complications, improving the rate of total tumor resection, and reducing postoperative complications.

THE X-RAY CALIBRATION PROJECT

Increasing the accuracy of information provided through X-Rays maximises pre-operative planning. Aim of this project is to determine the necessity of calibration probes that would improve the accuracy of pre-operative templating. This is a retrospective study involving leg length and pelvis X-Rays performed across the NHS Lanarkshire from 01/03/2023 until 31/04/2024.A total of 87 leg length X-Rays were identified, 18 had a calibration probe present. Leg length was measured on each and the X-Rays were calibrated against the existing probe. In 66.7% of cases there was a major leg length discrepancy of over 2cm between the pre-calibrated and post-calibrated X-Rays. Pelvic X-Rays of 80 patients that underwent total hip replacement were reviewed. Preoperative templating was compared to the implants inserted. An average of 1.94 discrepancy in the size of the acetabular implant was identified whilst in 30 cases the size of the femoral stem was incorrect by at least 1 size. Magnification of 119.7% on X-Rays was found to provide the most accurate templating. Seventy seven cases of pelvic X-Rays before and after hip hemiarthroplasty were also reviewed. The implant head was templated incorrectly in 74% of cases and the stem in 51%. It was identified that pelvic X-Ray magnification of 121.7% would provide the most accurate results.X-Rays with no calibration probes provide inaccurate measurements leading to faulty preoperative planning. Standardised use of a calibration sphere is strongly suggested and whenever that is not available, we suggest magnification of 121%.

Anatomy of Inferior Temporal Arteries in Relation to Middle Cranial Fossa Structures: A Postmortem Computed Tomography Angiography Study

Abstract Objective The inferior temporal arteries (ITAs), branches of the posterior cerebral artery (PCA), are critical vascular structures encountered during subtemporal surgical approaches. Anatomical data based on multiphase postmortem computed tomography angiography (MPMCTA) are provided as a tool for preoperative surgical planning to lower the risk of ITA injury. Methods Adult (≥18 years) cases that underwent MPMCTA during 2015 to 2023 and whose cause of death did not involve the cerebral circulation were included in the study. Standardized measurements on four predefined coronal slices in relation to the posterior clinoid process (PCP) were established with references to projections in axial and sagittal planes. The main aim was to assess the presence, width, and course of anterior ITA (AITA), middle ITA (MITA), and posterior (PITA) particularly within the individual established quadrants of the middle cranial fossa. Results A total of 74 hemispheres were studied among 37 patients with the mean age of 52 ± 20.2 years. PITA was present in 98.7% of studied hemispheres, followed by MITA in 90.7% and AITA in 89.2%. The course of PITA was straight (65.8%) or oblique (34.3%), with significant difference in mean width (p = 0.050), branching angle (p &lt; 0.001), distance to tentorial hiatus (p &lt; 0.001), and superior petrosal sinus (p &lt; 0.001). A pattern of PITA loop was defined as a twisting of its course within the collateral sulcus. Significant relationship between the presence of AITA and MITA (p &lt; 0.001) along with the co-presence of AITA and PITA (p = 0.029) was found. Conclusion Knowledge of ITA characteristics and their relationship to surrounding anatomical structures is vital in subtemporal neurosurgical interventions. Preoperative inspection of the collateral sulcus and its relation to the surgical trajectory is critical to prevent PITA injury.

A Deep Learning-Based Method for Rapid 3D Whole-Heart Modeling in Congenital Heart Disease.

This study aims to develop a deep learning-based method for generating three-dimensional heart mesh models for patients with congenital heart disease by integrating medical imaging and clinical diagnostic information. A deep learning model was trained using CT and cardiac MRI (CMR) images, along with clinical data from 110 patients. The web-based platform automatically outputs STL files for 3D printing and Unity 3D OBJ files for virtual reality (VR) applications upon uploading the medical images and diagnostic information. The models were tested on three congenital heart disease cases, with corresponding 3D printed and VR heart models generated. The 3D printed and VR heart models received high praise from professional doctors for their anatomical accuracy and clarity. Evaluations indicated that the proposed method effectively and rapidly reconstructs complex congenital heart disease structures, proving useful for preoperative planning and diagnostic support. The 3D modeling approach has the potential to enhance the precision of surgical planning and diagnosis for congenital heart disease. Future studies should explore larger datasets and training models for different types of congenital heart disease to validate the model's broad applicability.

Simulation of osteotomy in total knee arthroplasty with femoral extra-articular deformity assisted by artificial intelligence: a study based on three-dimensional models

BackgroundThe impact of extra-articular deformities (EADs) on lower limb alignment and collateral ligament integrity during total knee arthroplasty (TKA) poses significant challenges, increasing surgical complexity. Our study aims to evaluate the influence of EADs on mechanical axis alignment and the risk of collateral ligament injury during TKA using an AI-assisted surgical planning system, with the goal of minimizing ligament damage through precise and scientific planning.MethodsA healthy volunteer underwent CT and MRI scans of the lower limbs. The scan images were imported into Mimics 20.0 software, and the reconstructed models were spatially aligned using 3-maticResearch 11.0 software. Using Unigraphics NX9.0 software, 50 three-dimensional models of femoral lateral joint deformities with varying positions and angles were created. Finally, TKA was simulated using the AI JOINT preoperative planning system.ResultsThe larger the deformity angle and the closer it is to the knee joint, the more pronounced the deviation of the mechanical axis. During MA-aligned osteotomy, nine types of deformities can damage the collateral ligaments. After adjusting the varus/valgus of the prosthesis within a safe range of 3° and leaving a residual 3° varus/valgus in the lower limb alignment, only the 25° varus and 25° valgus deformities located at 90% of the femoral anatomical axis remain uncorrected.ConclusionFor patients with osteoarthritis and concurrent EAD undergoing TKA, using reconstructed 3D models of the collateral ligaments for preoperative planning helps visually assess collateral ligament damage, providing a practical solution. Minimizing intra-articular osteotomies within a safe range and allowing some residual alignment deviation can reduce the risk of collateral ligament injury.

Multi-stage automatic and rapid ablation and needle trajectory planning method for CT-guided percutaneous liver tumor ablation.

Computer-assisted planning methods have increasingly contributed to preoperative ablation planning; however, these methods cannot automatically obtain the final optimal solution within a short time and are rarely validated in practice, greatly limiting their clinical applicability. We aimed to propose a full-automatic multi-stage ablation and needle trajectory planning method for CT-guided percutaneous liver ablation to attain the final optimal plans under multiple clinical constraints rapidly. Our proposed method integrates the ablation zone planning fulfilling complete tumor coverage and critical structure avoidance while reaching a trade-off between ablation number and healthy tissue damage, and needle trajectory planning under multiple clinical constraints. Our needle trajectory planning determines feasible skin entry regions based on hard constraints, where the multi-objective optimization (MOO) considering soft constraints is performed using the Pareto Optimality and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods for the final optimal solution. The performance of our proposed method was evaluated on 30 tumors of various characteristics from 23 patients and clinically validated in five clinical cases. Our proposed method achieved 99.8% treatment zone coverage and 40.5% ablation efficiency without involving critical structures, and completely satisfied multiple clinical constraints in all needle trajectory planning results. The average planning time was 23.6 s for tumors of different sizes. All the plans were considered clinically acceptable by the doctors' evaluation. Our method achieved complete tumor coverage without complications in clinical case validation. Our proposed planning method can generate a final optimal plan satisfying multiple clinical constraints within a short time, potentially facilitating preoperative planning for hepatic tumor ablation.

The Usefulness of Portable Echo in the Preoperative Mapping of Lymphaticovenular Anastomosis.

This study evaluated the effectiveness of a pocket-sized ultrasound device in preoperative planning for lymphaticovenular anastomosis (LVA) to enhance lymphedema treatment outcomes. A retrospective analysis was performed on 24 patients who underwent LVA for secondary upper extremity lymphedema between June 2020 and August 2022. Patients were categorized into two groups: the ultrasound group, which used a pocket-sized device (Vscan Air), for preoperative vein identification, and a control group that did not. Preoperative lymphatic mapping was performed using indocyanine green lymphography, and suitable veins for anastomosis were identified using ultrasound. Upper extremity lymphedema index and incision length were compared. Participants in the ultrasound group had a shorter average incision length (2.85 ± 0.48 cm) than those in the control group (3.23 ± 0.78 cm, p = 0.038), indicating a more targeted and minimally invasive approach. Although volume reduction rates were not significantly different, the pocket ultrasound device facilitated more precise vein selection, enhancing surgical planning. Pocket-sized ultrasound devices provide a cost-effective and practical solution for vein identification during LVA, particularly in resource-limited settings. While high-frequency ultrasound offers superior resolution, portable devices could become standard tools for lymphatic surgery with continued technological advancement.

Augmented and virtual reality imaging for collaborative planning of structural cardiovascular interventions: a proof-of-concept and validation study.

Virtual reality (VR) and augmented reality (AR) have led to significant advancements in cardiac preoperative planning, shaping the world in profound ways. A noticeable gap exists in the availability of a comprehensive multi-user, multi-device mixed reality application that can be used in a multidisciplinary team meeting. A multi-user, multi-device mixed reality application was developed, supporting AR and VR implementations. Technical validation involved a standardized testing protocol and comparison of AR and VR measurements regarding absolute error and time. Preclinical validation engaged experts in interventional cardiology, evaluating the clinical applicability prior to clinical validation. Clinical validation included patient-specific measurements for five patients in VR compared with standard computed tomography (CT) for preoperative planning. Questionnaires were used at all stages for subjective evaluation. Technical validation, including 106 size measurements, demonstrated an absolute median error of 0.69mm (0.25 to 1.18mm) compared with ground truth. The time to complete the entire task was on average, with VR measurements being faster than AR ( versus , ). On clinical validation of five preoperative patients, there was no statistically significant difference between paired CT and VR measurements (0.58 [95% CI, to 2.74], ). Questionnaires showcased unanimous agreement on the user-friendly nature, effectiveness, and clinical value. The mixed reality application, validated through technical, preclinical, and clinical assessments, demonstrates precision and user-friendliness. Further research of our application is needed to validate the generalizability and impact on patient outcomes.

Current status and future of application of spinal surgery robot in spinal deformity surgery

At present, spinal surgical robots can be used for preoperative surgical planning, pedicle screw placement, and intervertebral processing and intervertebral fusion in spinal deformity surgery. Existing spinal surgical robots have become the main means for spinal surgery to improve surgical accuracy and safety and reduce surgical complications. However, the efficiency of robot-assisted spinal deformity surgery is lower than that of traditional surgery, and there are shortcomings such as low accuracy of robot screw placement and fewer integrated functions. This article reviews the current application status and future development trends of spinal surgical robots in spinal deformity surgery.

Comment on, "T2-FLAIR mismatch sign, an imaging biomarker for CDKN2A-intact in non-enhancing astrocytoma, IDH-mutant".

The study by Onishi et al. (2024) investigates the correlation between the T2-FLAIR mismatch sign and CDKN2A status in non-enhancing astrocytoma, IDH-mutant. Through the use of radiological and molecular pathological analyses, the research explores the potential of T2-FLAIR mismatch as an imaging biomarker for predicting CDKN2A-intact astrocytomas. Immunohistochemical staining and next-generation sequencing were employed to confirm molecular diagnosis, enhancing the study's robustness. While the findings contribute significantly to preoperative diagnostics and treatment planning, limitations exist. The relatively small sample size (31 patients) and exclusion of gadolinium-enhancing astrocytomas may restrict the generalizability of the results. Additionally, variation in imaging protocols and the retrospective nature of the study limit the overall impact. Future research with a larger cohort, standardized imaging protocols, and a prospective design is recommended to validate the clinical utility of T2-FLAIR mismatch in differentiating CDKN2A status in astrocytomas.

Proximal Humerus Reconstruction in Skeletally Immature Patients

Proximal humerus reconstruction after oncologic resection is complex, with numerous muscular attachments, proximity of critical neurovascular structures, and dynamic stability granting multidirectional motion at the glenohumeral articulation. In skeletally immature patients, additional factors increase the complexity, including remaining limb growth and humerus size. Limb length discrepancy affects the limb's esthetics and function while the humerus size can limit fixation strategies and intramedullary device use. Reconstruction options used in isolation or combination include endoprostheses, osteoarticular allografts, allograft-prosthetic composites, autografts, and arthrodesis. Unique limb salvage options to address the unique factors in young, skeletally immature patients include vascularized fibular epiphyseal transfer, claviculo pro humeri, and expandible endoprostheses. Each option has advantages and disadvantages for anticipated function, durability, shoulder stability, and complications. This review aims to aid preoperative planning and decision making for surgeons and patients undergoing proximal humerus resection and reconstruction with notable remaining growth potential.