Anatomical Models Research Articles

Evaluation of a novel nerve ablation technique to relieve lower back pain: A cadaveric feasibility pilot study.

Radiofrequency ablation is a treatment for facetogenic low back pain that targets medial branches of lumbar dorsal rami to denervate facet joints. Clinical outcomes vary; optimizing cannula placement to better capture the medial branch may improve clinical outcomes. A novel parasagittal technique was proposed from an anatomical model; this technique was proposed to optimize capture of the medial branch. The anatomical feasibility of the novel technique has not been evaluated. To simulate and evaluate the proposed parasagittal technique in its ability to achieve proper cannula placement, and proximity of uninsulated cannula tips to the medial branches of the dorsal rami in cadaveric specimens. Under fluoroscopic guidance, 14 cannulae were placed using the parasagittal technique targeting the lumbar medial branches of two cadavers. Meticulous dissection was undertaken to assess cannula alignment and measure proximities to target nerves using a digital caliper. The novel parasagittal technique was successfully performed in a cadaveric model in 12/14 attempts. The technique achieved close proximity of cannula tips to medial branches (0.8 ± 1.1 mm). In two instances cannulae were placed unsuccessfully, where one cannula was too far anterior, the other too far retracted. In this cadaveric simulation study, the feasibility of performing the parasagittal technique for lumbar radiofrequency ablation was evaluated. This study suggests the parasagittal technique is a feasible option for lumbar medial branch radiofrequency ablation.

Safety of non-invasive brain stimulation in patients with implants: a computational risk assessment.

Non-invasive brain stimulation (NIBS) methodologies, such as transcranial electric (tES) are increasingly employed for therapeutic, diagnostic, or research purposes. The concurrent presence of active/passive implants can pose safety risks, affect the NIBS delivery, or generate confounding signals. A systematic investigation is required to understand the interaction mechanisms, quantify exposure, assess risks, and establish guidance for NIBS applications. We used measurements, simplified generic, and detailed anatomical modeling to: (i) systematically analyze exposure conditions with passive and active implants, considering local field enhancement, exposure dosimetry, tissue heating and neuromodulation, capacitive lead current injection, low-impedance pathways between electrode contacts, and insulation damage; (ii) identify risk metrics and efficient prediction strategies; (iii) quantify these metrics in relevant exposure cases and (iv) identify worst case conditions. Various aspects including implant design, positioning, scar tissue formation, anisotropy, and frequency were investigated. At typical tES frequencies, local enhancement of dosimetric exposure quantities can reach up to one order of magnitude for deep brain stimulation (DBS) and stereoelectroencephalography implants (more for elongated passive implants), potentially resulting in unwanted neuromodulation that can confound results but is still 2-3 orders of magnitude lower than active DBS. Under worst-case conditions, capacitive current injection in the active implants' lead can produce local exposures of similar magnitude as the passive field enhancement, while capacitive pathways between contacts are negligible. Above 10 kHz, applied current magnitudes increase, necessitating consideration of tissue heating. Furthermore, capacitive effects become more prominent, leading to current injection that can reach DBS-like levels. Adverse effects from abandoned/damaged leads in direct electrode vicinity cannot be excluded. Safety related concerns of tES application in the presence of implants are systematically identified and explored, resulting in specific and quantitative guidance and establishing basis for safety standards. Furthermore,several methods for reducing risks are suggested while acknowledging the limitations(see Sec. 4.5).

Oblique or short incisions reduce the risk of saphenous nerve damage during hamstrings harvesting. A model for mapping nerve pathways at the harvest site.

INTRODUCTIONHamstring autografts are frequently used for ligament reconstruction surgery. Twelve to 84% of patients describe hypo or dysaesthesia secondary to injury of the saphenous nerve or one of its branches after hamstring harvesting. Type of incision (orientation and length) is subject of much debate to limit the risk of nerve damage. A cadaveric study was performed to determine which type of incision limits the risk of injury to the saphenous nerve or one of its branches, based on an anatomic model for mapping nerve pathways at the harvest site. METHODSAn anatomical study was performed on 20 knees from 12 embalmed bodies. Distance between saphenous nerve branches and 4 points of interest along the tibial crest was measured. Based on these measurements, a digital model of the saphenous nerve and its branches was created. A model of three common types of incision (vertical, horizontal and oblique) was overlaid. Each incision was modelled for three lengths (2, 3 and 4cm). Percentage of collision between nerve course model and incision model was then calculated to determine the risk of nerve damage for each type of incision. Based on the nerve course model, a “low collision risk” safe zone was identified. RESULTSNerve damage risk after an oblique incision was significantly lower than for a horizontal or vertical incision, for incision lengths of 3 and 4cm (p<0.05). For a specific incision orientation, the length of the incision did not affect the risk of nerve damage. A trapezoidal space close to the tibial crest and distal to the anterior tibial tuberosity appears to reduce risk of nerve damage. CONCLUSIONThis cadaveric study suggests that during hamstring harvesting, incisions shorter than 2cm reduce the risk of saphenous nerve’s branches injuries. For incisions longer than 2cm, using an oblique incision may reduce the risk compared to vertical or horizontal incisions. LEVEL OF EVIDENCELevel of evidence not applicable: Laboratory experiments

Neurosurgical applications of the exoscope: from in vitro studies to real-life surgical use in selective dorsal rhizotomy

BackgroundThe microscope has been the gold standard in neurosurgical practice due to its ability to magnify anatomical structures. However, it has limitations, including restricted visual fields and ergonomic challenges that can lead to surgeon fatigue and musculoskeletal issues. The exoscope is an emerging technology that may address these limitations by offering comparable magnification with improved ergonomics. MethodsThis study compares the traditional microscope (KINEVO 900) with a 3D digital exoscope (Aeos Digital Microscope) in visual field width, image sharpness, and ergonomic impact. Visual field assessments were conducted using millimeter paper at a fixed distance, while image sharpness was evaluated using graph paper with pins at different depths. Ergonomic evaluation involved simulating surgical positions using a spine anatomical model. The practical applicability was tested during Selective Dorsal Rhizotomy (SDR) procedures, comparing the surgeon's experience with both devices over 20 consecutive cases. ResultsThe exoscope provided a larger visual field (81.18 cm2) compared to the microscope's (54.10 cm2). Image sharpness was similar for both devices across various depths and zoom levels. Ergonomically, the exoscope allowed the surgeon to maintain a neutral posture while visualizing extreme angles, unlike the microscope, which required significant upper body movement. In SDR procedures, the exoscope improved surgeon comfort and interaction with the operating team, despite an initial learning curve. ConclusionsThe exoscope presents notable advantages in terms of visual field and ergonomics. The exoscope’s ability to facilitate better posture and team communication without compromising image quality makes it an addition to neurosurgical practice, as in SDR.

3D Bioprinting Strategies for Melatonin‐Loaded Polymers in Bone Tissue Engineering

AbstractBone pathologies are still among the most challenging issues for orthopedics. Over the past decade, different methods are developed for bone repair. In addition to advanced surgical and graft techniques, polymer‐based biomaterials, bioactive glass, chitosan, hydrogels, nanoparticles, and cell‐derived exosomes are used for bone healing strategies. Owing to their variation and promising advantages, most of these methods are not translated into clinical practice. Three dimensonal (3D) bioprinting is an additive manufacturing technique that has become a next‐generation biomaterial technique adapted for anatomic modeling, artificial tissue or organs, grafting, and bridging tissues. Polymer‐based biomaterials are mostly used for the controlled release of various drugs, therapeutic agents, mesenchymal stem cells, ions, and growth factors. Polymers are now among the most preferable materials for 3D bioprinting. Melatonin is a well‐known antioxidant with many osteoinductive properties and is one of the key hormones in the brain–bone axis. 3D bioprinted melatonin‐loaded polymers with unique lipophilic, anti‐inflammatory, antioxidant, and osteoinductive properties for filling large bone gaps following fractures or congenital bone deformities may be developed in the future. This study summarized the benefits of 3D bioprinted and polymeric materials integrated with melatonin for sustained release in bone regeneration approaches.

3D Model Simulation in Preoperative Planning of Complex and Revision Hip Replacement

Complex and revision hip arthroplasty has remained one of the most discussed orthopedic topics in recent years. With the advancement of printing technologies 3D preoperative planning and live model simulation provides us with “hands on” procedures without any risk for the patient. Modern computer technologies present the possibility for preoperative planning of Total Hip Arthroplasty (THA) in digital environment. 3D printing of anatomical models in real size allows accurate assessment of the pathological deviations of the anatomy, precise preoperative planning of the reconstruction and simulation of the operative intervention ex-vivo. We present a series of 3D simulations for planning hip replacement, illustrating the technique, discussing its advantages and disadvantages, in complex primary and revision hip arthroplasty. In the complex and revision surgery of the hip joint, a correct assessment of bone defects is mandatory. Reconstructing the biomechanical parameters – centre of rotation, femoral offset and leg length discrepancy, is also of great significance. The 3D reconstruction with biomodel simulations offers exceptional accuracy in this respect. The method can be an excellent tool for education of surgeons in training and residents.

Activation thresholds for electrical phrenic nerve stimulation at the neck: evaluation of stimulation pulse parameters in a simulation study

Abstract Objective. Phrenic nerve stimulation reduces ventilator-induced-diaphragmatic-dysfunction, which is a potential complication of mechanical ventilation. Electromagnetic simulations provide valuable information about the effects of the stimulation and are used to determine appropriate stimulation parameters and evaluate possible co-activation.&amp;#xD;Approach. Using a multiscale approach, we built a novel detailed anatomical model of the neck and the phrenic nerve. The model consisted of a macroscale volume conduction model of the neck with 13 tissues, a mesoscale volume conduction model of the phrenic nerve with three tissues, and a microscale biophysiological model of axons with diameters ranging from 5 to 14 μm based on the McIntyre-Richardson-Grill-model for myelinated axons. This multiscale model was used to quantify activation thresholds of phrenic nerve fibers using different stimulation pulse parameters (pulse width, interphase delay, asymmetry of biphasic pulses, pulse polarity, and rise time) during non-invasive electrical stimulation. Electric field strength was used to evaluate co-activation of the other nerves in the neck.&amp;#xD;Main results. For monophasic pulses with a pulse width of 150 μs, the activation threshold depended on the fiber diameter and ranged from 20 to 156 mA, with highest activation threshold for the smallest fiber diameter. The relationship was approximated using a power fit function x^−3. Biphasic (symmetric) pulses increased the activation threshold by 25 to 30 %. The use of asymmetric biphasic pulses or an interphase delay lowered the threshold close to the monophasic threshold. Possible co-activated nerves were the more superficial nerves and included the transverse cervical nerve, the supraclavicular nerve, the great auricular nerve, the cervical plexus, the brachial plexus, and the long thoracic nerve.&amp;#xD;Significance. Our multiscale model and electromagnetic simulations provided insight into phrenic nerve activation and possible co-activation by non-invasive electrical stimulation and provided guidance on the use of stimulation pulse types with minimal activation threshold.

Robust optimization incorporating weekly predicted anatomical CTs in IMPT of nasopharyngeal cancer.

Objective.This study proposes a robust optimization (RO) strategy utilizing virtual CTs (vCTs) predicted by an anatomical model in intensity-modulated proton therapy (IMPT) for nasopharyngeal cancer (NPC).Methods and Materials.For ten NPC patients, vCTs capturing anatomical changes at different treatment weeks were generated using a population average anatomy model. Two RO strategies of a 6 beams IMPT with 3 mm setup uncertainty (SU) and 3% range uncertainty (RU) were compared: conventional robust optimization (cRO) based on a single planning CT (pCT), and anatomical RO incorporating 2 and 3 predicted anatomies (aRO2 and aRO3). The robustness of these plans was assessed by recalculating them on weekly CTs (week 2-7) and extracting the voxel wise-minimum and maximum doses with 1 mm SU and 3% RU (voxmin\voxmax1mm3%).Results.The aRO plans demonstrated improved robustness in high-risk CTV1 and low-risk CTV 2 coverage compared to cRO plans. The weekly evaluation showed a lower plan adaptation rate for aRO3 (40%) vs. cRO (70%). The weekly nominal and voxmax1mm3%doses to OARs, especially spinal cord, are better controlled relative to their baseline doses at week 1 with aRO plans. The accumulated dose analysis showed that CTV1&2 had adequate coverage and serial organs (spinal cord and brainstem) were within their dose tolerances in the voxmin\voxmax1mm3%, respectively.Conclusion.Incorporating predicted weekly CTs from a population based average anatomy model in RO improves week-to-week target dose coverage and reduces false plan adaptations without increasing normal tissue doses. This approach enhances IMPT plan robustness, potentially facilitating reduced SU and further lowering OAR doses.

An online workshop to raise awareness of pelvic floor in track and field female athletes: a quasi-experimental study.

Track and field is a high-impact sport that may facilitate pelvic floor dysfunction (PFD) of females. Although increasing the information may reduce deleterious habits, the traditional workshops to date did not motivate and engage the female athletes. This study aimed to evaluate the effects of an online educational workshop about pelvic floor awareness on knowledge and habits of track and field female athletes. A total of 49 track and field athletes participated in this quasi-experimental study: 38 attended an educational workshop and 11 did not. The workshop included innovative resources, such as 3D anatomic models, practical proprioceptive exercises guided by physiotherapists, and an anonymous questions and answers section. Before and 1month later, all the athletes fulfilled an anonymous questionnaire to assess their knowledge about urinary incontinence (UI), ano-rectal incontinence (ARI), pelvic organ prolapse (POP) and female sexual dysfunction (FSD), as well as toileting and sports habits. After attending the workshop, athletes obtained higher scores in knowledge about ARI (p = 0.019), POP (p < 0.001), and FSD (p = 0.018) compared to baseline and athletes who did not attend it. No improvements were observed in habits and knowledge about UI (p > 0.05). The athletes who reached 70% of correct responses about POP had greater number of healthy habits than the rest of the athletes. An innovative educational workshop about pelvic floor increases knowledge of track and field female athletes but is insufficient to modify their habits. Sports and health professionals should design educational strategies to manage the most unknown topics about pelvic floor care, considering that the proposed methodology and innovative resources are effective to increase knowledge.

A combined radiomics and anatomical features model enhances MRI-based recognition of symptomatic nerves in primary trigeminal neuralgia

A combined radiomics and anatomical features model enhances MRI-based recognition of symptomatic nerves in primary trigeminal neuralgia

Male Linear Anthropometrics of Selected Nigerian Ethnicities: A Cross - Sectional Analysis

Introduction: This study aims at evaluating selected linear anthropometrics of three Nigerian ethnic groups to provide baseline data for the creation of 3D Negroid anatomic models. Methods: The research design was a cross-sectional design. The sampling technique was multistage proportionate random sampling. The places of study were Imo, Oyo, and Kano States of Nigeria. The study lasted for one (1) year. Random selection of 1500 adult males from three major tribes (500 Igbo, 500 Yoruba, and 500 Hausa between the ages of 18 and 40 years). Tukey’s Post Hoc test of multiple comparisons was carried out to determine the specific ethnic groups that differ in specific anthropometric parameters. Results: The differences in standing height, arm length, and thigh length across the Hausa, Igbo, and Yoruba ethnic groups are statistically significant (p &lt; 0.05). Conclusion: The study concluded that the Igbo and Yoruba groups had higher standing heights compared to the Hausa group. Arm length was longer in the Igbo and Yoruba groups compared to the Hausa group. However, thigh length was greater in the Hausa group compared to both the Igbo and Yoruba groups, while the Hausa group had longer thigh lengths than both the Igbo and Yoruba groups. The Igbo group displayed the largest arm span, whereas the Hausa group had the widest shoulder breadth. However, the Hausa group had a lower bi-iliac breadth in comparison to the other two ethnic groups.

Source Localization and Classification of Pulmonary Valve-Originated Electrocardiograms Using Volume Conductor Modeling with Anatomical Models.

Premature ventricular contractions (PVCs) are a common arrhythmia characterized by ectopic excitations within the ventricles. Accurately estimating the ablation site using an electrocardiogram (ECG) is crucial for the initial classification of PVC origins, typically focusing on the right and left ventricular outflow tracts. However, finer classification, specifically identifying the left cusp (LC), anterior cusp (AC), and right cusp (RC), is essential for detailed preoperative planning. This study aims to improve the accuracy of cardiac waveform source estimation and classification in 27 patients with PVCs originating from the pulmonary valve. We utilized an anatomical human model and electromagnetic simulations to estimate wave source positions from 12-lead ECG data. Time-series source points were identified for each measured ECG waveform, focusing on the moment when the distance between the estimated wave source and the pulmonary valve was minimal. Computational analysis revealed that the distance between the estimated wave source and the pulmonary valve was reduced to less than 1 cm, with LC localization achieving errors under 5 mm. Additionally, 74.1% of the subjects were accurately classified into the correct origin (LC, AC, or RC), with each origin demonstrating the highest percentage of subjects corresponding to the targeted excitation origin. Our findings underscore the novel potential of this source localization method as a valuable complement to traditional waveform classification, offering enhanced diagnostic precision and improved preoperative planning for PVC ablation procedures.

The Decontamination Effect of an Oscillating Chitosan Brush Compared With an Ultrasonic PEEK-Tip: An InVitro Study Using a Dynamic Biofilm Model.

This study aimed to assess the effect of an oscillating chitosan brush (OCB) compared with an ultrasonic device with PEEK tip (US-PEEK) for mechanical implant surface decontamination using an invitro model combining 3D models and a validated dynamic multispecies biofilm. A multispecies biofilm using six bacterial strains (Streptococcus oralis, Veillonella parvula, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans) was seeded on dental implants with machined and sandblasted, large-grit and acid-etched (SLA) surfaces. These were installed in 3D models depicting peri-implant defect. Mechanical decontamination was performed for 120 s using either an OCB or a US-PEEK. A negative control group received no treatment. Scanning electron microscopy (SEM) was used to evaluate the bacterial composition and quantitative PCR (qPCR) analyzed the number of each bacterial species [colony-forming units per milliliter (CFU/mL)]. Well-structured biofilms with a dense microbial distribution were observed on the negative control implants after 72 h. qPCR following mechanical decontamination showed a scarce bacterial reduction in the OCB group. The US-PEEK group exhibited a significant decrease in bacterial species compared to both OCB and control groups (p < 0.05). A biofilm removal effect was also observed in the OCB group for the machined implant surfaces. In vitro assessment using an anatomical 3D model showed that mechanical decontamination effectively reduced biofilm. The US-PEEK group demonstrated biofilm reduction on the SLA surface, while the OCB group showed a reduction on the machined implant surface. Additionally, the US-PEEK group demonstrated greater efficacy in reducing bacterial numbers.

Current Applications of the Three-Dimensional Printing Technology in Neurosurgery: A Review.

In the recent years, three-dimensional (3D) printing technology has emerged as a transformative tool, particularly in health care, offering unprecedented possibilities in neurosurgery. This review explores the diverse applications of 3D printing in neurosurgery, assessing its impact on precision, customization, surgical planning, and education. A literature review was conducted using PubMed, Web of Science, Embase, and Scopus, identifying 84 relevant articles. These were categorized into spine applications, neurovascular applications, neuro-oncology applications, neuroendoscopy applications, cranioplasty applications, and modulation/stimulation applications. 3D printing applications in spine surgery showcased advancements in guide devices, prosthetics, and neurosurgical planning, with patient-specific models enhancing precision and minimizing complications. Neurovascular applications demonstrated the utility of 3D-printed guide devices in intracranial hemorrhage and enhanced surgical planning for cerebrovascular diseases. Neuro-oncology applications highlighted the role of 3D printing in guide devices for tumor surgery and improved surgical planning through realistic models. Neuroendoscopy applications emphasized the benefits of 3D-printed guide devices, anatomical models, and educational tools. Cranioplasty applications showed promising outcomes in patient-specific implants, addressing biomechanical considerations. The integration of 3D printing into neurosurgery has significantly advanced precision, customization, and surgical planning. Challenges include standardization, material considerations, and ethical issues. Future directions involve integrating artificial intelligence, multimodal imaging fusion, biofabrication, and global collaboration. 3D printing has revolutionized neurosurgery, offering tailored solutions, enhanced surgical planning, and invaluable educational tools. Addressing challenges and exploring future innovations will further solidify the transformative impact of 3D printing in neurosurgical care. This review serves as a comprehensive guide for researchers, clinicians, and policymakers navigating the dynamic landscape of 3D printing in neurosurgery.

An open-access lumbosacral spine MRI dataset with enhanced spinal nerve root structure resolution

Spinal cord injury (SCI) profoundly affects an individual’s ability to move. Fortunately, recent advancements in neuromodulation, particularly the spatio-temporal epidural electrical stimulation (EES) targeting the spinal nerve roots, promoted rapid rehabilitation of SCI patients. Such neuromodulation techniques require precise anatomical modelling of spinal cord. However, the lack of spine imaging datasets, especially high-quality magnetic resonance imaging (MRI) datasets highlighting nerve roots, hinders the translation of EES into medical practice. To address this problem, we introduce an open-access lumbosacral spine MRI dataset acquired in 14 healthy adults, using constructive interference in steady state (CISS) sequence, double echo steady state (DESS) sequence, and T2-weight turbo spin echo (T2-TSE) sequence, with enhanced nerve root resolution. The dataset also includes the corresponding anatomical annotations of nerve roots and the final reconstructed 3D spinal cord models. The quality of our dataset is assessed using image quality metrics implemented in MRI quality control tool (MRIQC). Our dataset provides a valuable platform to promote a wide range of spinal cord neuromodulation research and collaboration among neurorehabilitation engineers.

Biomechanical investigation of positive reduction in the femoral neck fracture: a finite element analysis.

Gotfried positive reduction offers an alternative strategy for femoral neck fracture (FNF) when achieving anatomical reduction is challenging. However, the biomechanical consequences of positive reduction remain unclear. The purpose of this study was to investigate the biomechanical behavior of positive reduction across different Pauwels classification, providing a reference for quantifying positive reduction in clinical practice. Three-dimensional (3D) models of FNF were established and categorized according to the Pauwels classifications (Pauwels I, II, and III), each of them contained seven models with different reduction qualities, including an anatomical reduction model, two negative reduction models, and four positive reduction models, all of which were stabilized with dynamic hip screws (DHS) and cannulated screws (CS). We investigated the maximal von-Mises stress of internal fixation and proximal femoral, femoral fragment displacement, and maximal von-Mises strain at the proximal fragment fracture site when a 2100N load was applied to the femoral head. The maximum von-Mises stress on the internal fixators in each Pauwels group was lowest in the anatomical reduction model. In the Pauwels I group, positive reduction exceeding 3mm resulted in the maximum von-Mises stress on the internal fixators surpassing that of the negative reduction model. For the Pauwels II group, positive reduction beyond 2mm led to the maximum von-Mises stress on the internal fixators exceeding that of the negative reduction model. In the Pauwels III group, positive reduction beyond 1mm caused the maximum von-Mises stress on the internal fixators to be higher than that of the negative reduction model. The maximum von-Mises strain at the fracture site of proximal femur fragment increased with positive reduction. Varus displacement increased in positive reduction models as the Pauwels angle rose, potentially exacerbating rotation deformity in Pauwels III group. Excessive positive reduction may increase the risk of FNF failure after internal fixation. From a biomechanical stability perspective, positive reduction should be limited to 3mm or below in the Pauwels I group, restricted to not exceed 2mm in the Pauwels II group, and should not exceed 1mm in the Pauwels III group. Negative reduction should be avoided in all Pauwels groups.

Creation of a replicable anatomic model of terrible triad of the elbow.

Terrible triad of the elbow (TTE) is a complex dislocation associating radial head (RH) and coronoid process (CP) fractures. There is at present no reproducible anatomic model for TTE, and pathophysiology is unclear. The main aim of the present study was to create and validate an anatomic model of TTE. Secondary objectives were to assess breaking forces and relative forearm rotation with respect to the humerus before dislocation. An experimental comparative study was conducted on 5 fresh human specimens aged 87.4 ± 8.6 years, testing 10 upper limbs. After dissection conserving the medial and lateral ligaments, interosseous membrane and joint capsule, elbows were reproducibly positioned in maximal pronation and 15° flexion, for axial compression on a rapid (100mm/min) or slow (10mm/min) protocol, applied by randomization between the two elbows of a given cadaver, measuring breaking forces and relative forearm rotation with respect to the humerus before dislocation. The rapid protocol reproduced 4 posterolateral and 1 divergent anteroposterior TTE, and the slow protocol 5 posterolateral TTE. Mean breaking forces were 3,126 ± 1,066N for the lateral collateral ligament (LCL), 3,026 ± 1,308N for the RH and 2,613 ± 1,120N for the CP. Comparing mean breaking forces for all injured structures in a given elbow on the rapid protocol found a p-value of 0.033. Comparison of difference in breaking forces in the three structures (LCL, RH and CP) between the slow and rapid protocols found a mean difference of -4%. Mean relative forearm rotation with respect to the humerus before dislocation was 1.6 ± 1.2° in external rotation. We create and validate an anatomic model of TTE by exerting axial compression on an elbow in 15° flexion and maximal pronation at speeds of 100 and 10mm/min.

Planning for complex inferior vena cava filter retrievals: the implementation and effectiveness of 3D printed models

BackgroundInferior vena cava filter (IVC) retrieval is most often routine but can be challenging with high morbidity in complex cases, especially those with an extended dwelling time. While risk of morbidity in complex retrievals is decreased with advanced filter retrieval techniques, deciding when and which to use these requires detailed pre-procedural planning. The purpose of our study was to evaluate patient-specific 3D printed anatomic IVC filter models for aiding complex IVC filter retrievals.MethodsAll IVC filter retrieval patients between June 2021 and September 2022 at one academic medical hospital were prospectively screened. Nine met criteria for complex retrieval, and their CT images were used to 3D print patient-specific IVC and filter models. Models were used in pre-procedural planning and clinical utility was assessed using the Anatomic Model Utility Likert Questionnaire and estimations of the procedural and fluoroscopy time saved.ResultsThe usage of 3D printed models in pre-procedural planning had high clinical utility based on the Likert questionnaire (Anatomic Model Utility Points 366.7 ± 103.1). Using a model significantly increased confidence in planning (p = 0.03) and modified the treatment plan in seven cases. It also led to cost-efficient use of resources in the procedure suite with estimated reduction in procedure and fluoroscopy time of 29.0 [20.3] (p = 0.003) and 10.2 [6.7] (p = 0.002) minutes, respectively.Conclusion3D printed anatomic models for patients who require complex IVC filter retrieval demonstrated Likert-based high clinical utility and led to estimated reductions of procedural and fluoroscopy time.

4D-Flow MRI and Vector Ultrasound in the In-Vitro Evaluation of Surgical Aortic Heart Valves - a Pilot Study.

The aim of this study was the initial investigation of 4D-Flow MRI and Vector Ultrasound as novel imaging techniques in the in-vitro analysis of hemodynamics in anatomical models. Specifically, by looking at the hemodynamic performance of state-of-the-art surgical heart valves in a 3D-printed aortic arch. The mock circulatory loop simulated physiological, pulsatile flow. Two mechanical and three biological aortic valves prostheses were compared in a 3D-printed aortic arch. 4D magnetic resonance imaging and vector flow Doppler ultrasound served as imaging methods. Hemodynamic parameters such as wall shear stress, flow velocities and pressure gradients were analyzed. The flow analysis revealed characteristic flow-patterns in the 3D-printed aortic arch. The blood-flow in the arch presented complex patterns, including the formation of helixes and vortices. Higher proximal peak velocities and lower flow volumes were found for biological valves. The mock circulatory loop in combination with modern radiological imaging provides a sufficient basis for the hemodynamic comparison of aortic valves.

Impact of 3D-Printed Anatomical Models on Doctor-Patient Communication in Orthopedic Consultations: A Randomized Clinical Trial.

Effective communication between doctors and patients is essential for treatment adherence and better clinical outcomes. Although 3D printing has advanced in medicine, its impact on doctor-patient communication still requires further investigation. This randomized clinical trial evaluated the effectiveness of 3D anatomical models as a tool to facilitate communication in orthopedic consultations. This randomized clinical trial was conducted between May 2024 and September 2024, with 46 patients randomized into two groups: 21 patients received medical explanations with the aid of 3D models, and 25 without. Patients' knowledge was assessed before and after the consultation, and the quality of communication was measured using the Communication Assessment Tool (CAT). In the group using 3D models, 76.19% of patients reported improved knowledge of their conditions, while in the group without models, the increase was 52.00%. Additionally, 14 out of 15 CAT parameters showed statistically significant differences between the groups, with p-values ranging from 0.001 to 0.021. The use of 3D models significantly improved patients' understanding and facilitated communication with doctors, proving to be an effective tool for explaining complex medical conditions.