Individual Anatomy Research Articles

Impact of Individual Spinopelvic Anatomy on the Localization and Severity of Symptomatic Isthmic Spondylolisthesis.

Retrospective analysis of prospectively collected data. Isthmic spondylolisthesis (iSPL) occurs most commonly in L5/S1 and L4/5. This study investigates the association between spinopelvic anatomy and the pathogenesis of iSPL. Spinopelvic parameters as well as severity of slip grade were measured in sagittal spine radiographs of symptomatic patients with iSPL in segments L4/5 and L5/S1. Means were calculated and differences between both groups were analyzed. A correlation between the analyzed parameters and degree of slippage was performed. We included 73 subjects in this study; 11 in L4/5 group and 62 in L5/S1 group. Pelvic anatomy significantly differed between L4/5 and L5/S1 iSPL (Pelvic Incidence (PI) 54.8° vs 66.3°, P value = .006; Pelvic Radius (PR) 124.4mm vs 137.4mm; P value = .005 and Sacral Table Angle (STA) 101.0° vs 92.2°, P value < .001). The relative degree of slippage was significantly higher in the L5/S1 group (L4/5 29.1% vs L5/S1 40.1%, P value .022). We also observed a significant correlation between pelvic anatomy and the severity of the slip in iSPL at the L5/S1 level. Pelvic parameters PI and STA play an important role concerning the level of occurrence and severity of iSPL. Spinopelvic anatomy determines the pathogenesis of iSPL.

Novel Movable Typing for Personalized Vein‐Chips in Large Scale: Recapitulate Patient‐Specific Virchow's Triad and its Contribution to Cerebral Venous Sinus Thrombosis (Adv. Funct. Mater. 23/2023)

Organ on Chips In article number 2214179, Lining Arnold Ju and co-workers, devised a novel, cost-effective, and high-throughput fabrication method for the creation of personalized vein-chips, employing movable typing stereolithography and organ-on-chip technologies. This innovative chip accurately replicates an individual patient's unique anatomy and hemodynamics, thereby facilitating the investigation of clot formation in cerebral venous sinus thrombosis. The vein-chip demonstrates significant potential for future personalized thrombotic assessment and monitoring.

ID: 197800 Image-Guided Programming Reduces Initial DBS Programming Time in Parkinson's Disease Patients

Optimization of Deep Brain Stimulation (DBS) programming usually consists of an empirical trial-and-error process involving appraisal of various stimulation parameters to determine optimal settings. This process can be inefficient, lengthy, and burdensome for the patient. The use of a visualization tool capable of illustrating the location of the DBS lead within the individual's segmented anatomy and volume of tissue activated (VTA) may have the potential to reach optimal stimulation parameters in a shorter, more efficient fashion.

Motor point heatmap guide for neuromuscular electrical stimulation of the quadriceps muscle

To create an anatomical chart that indicates the probability of finding a motor point (MP) in different areas of the quadriceps muscle. On 31 healthy adults, the individual anatomy of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) was determined using ultrasound. Thereafter, a 3Hz neuromuscular electrical stimulation (NMES) MP-search with a MP-pen was performed. The thigh anatomy was normalized and divided into 112 (8x14) 3x3cm areas, and the probability of finding a MP in the different areas was calculated to create a MP heat-map. The heat-map displayed the two best 3x3cm areas, over VL and VM respectively, each with a probabilitygreater than50% of finding a MP and a higher probability compared to all other areas (p<.05). RF exhibited two areas with a 29% probability of finding a MP. A higher number of MPs on the quadriceps, mean (±SD) 9.4±1, was in regression analysis found to be significantly associated with two independent factors higher physical activity level and lower body fat (R2=0.42, p=<.0001). Large inter-individual variations in location, and number of MPs were found, but the heat-map displayed areas with higher probability of finding a MP and can be used to facilitate NMES-application.

Recurrent neural networks for generalization towards the vessel geometry in autonomous endovascular guidewire navigation in the aortic arch

PurposeEndovascular intervention is the state-of-the-art treatment for common cardiovascular diseases, such as heart attack and stroke. Automation of the procedure may improve the working conditions of physicians and provide high-quality care to patients in remote areas, posing a major impact on overall treatment quality. However, this requires the adaption to individual patient anatomies, which currently poses an unsolved challenge.MethodsThis work investigates an endovascular guidewire controller architecture based on recurrent neural networks. The controller is evaluated in-silico on its ability to adapt to new vessel geometries when navigating through the aortic arch. The controller’s generalization capabilities are examined by reducing the number of variations seen during training. For this purpose, an endovascular simulation environment is introduced, which allows guidewire navigation in a parametrizable aortic arch.ResultsThe recurrent controller achieves a higher navigation success rate of 75.0% after 29,200 interventions compared to 71.6% after 156,800 interventions for a feedforward controller. Furthermore, the recurrent controller generalizes to previously unseen aortic arches and is robust towards size changes of the aortic arch. Being trained on 2048 aortic arch geometries gives the same results as being trained with full variation when evaluated on 1000 different geometries. For interpolation a gap of 30% of the scaling range and for extrapolation additional 10% of the scaling range can be navigated successfully.ConclusionAdaption to new vessel geometries is essential in the navigation of endovascular instruments. Therefore, the intrinsic generalization to new vessel geometries poses an essential step towards autonomous endovascular robotics.

Evaluation of the prognostic value of the anatomical characteristics of the bony structures in the shoulder in bursal-sided partial-thickness rotator cuff tears.

In recent studies, individual scapular anatomy has been found to be related to degenerative full-thickness rotator cuff tears. However, research on the relationship between the anatomical characteristics of shoulder radiographs and bursal-sided partial-thickness rotator cuff tears (PTRCTs) is limited, and the risk factors for this pathology still need to be determined. The bursal-sided PTRCTs group included 102 patients without a history of shoulder trauma who underwent arthroscopy between January 2021 and October 2022. A total of 102 demographically matched outpatients with intact rotator cuffs were selected as the control group. Radiographs were used to measure the lateral acromial angle (LAA), critical shoulder angle (CSA), greater tuberosity angle (GTA), β-angle, acromion index (AI), acromiohumeral distance (AHD), acromial tilt (AT), acromial slope (AS), acromial type, and acromial spur by two independent observers. Multivariate analyses of these data were used to identify potential risk factors for bursal-sided PTRCTs. Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of CSA, GTA, and AI for this type of pathology. The β-angle, AHD, AS and acromion type showed no difference between bursal-sided PTRCTs and controls (p = 0.009, 0.200, 0.747 and 0.078, respectively). CSA, GTA and AI were significantly higher in bursal-sided PTRCTs (p < 0.001). LAA, β-angle and AT were significantly lower in bursal-sided PTRCTs. Multivariate logistic regression analysis demonstrated significant correlations between the acromial spur (p = 0.024), GTA (p = 0.004), CSA (p = 0.003) and AI (p = 0.048) and bursal-sided PTRCTs. The areas under the ROC curves for AI, CSA, and GTA were 0.655 (95% CI 0.580-0.729), 0.714 (95% CI 0.644-0.784), and 0.695 (95% CI 0.622-0.767), respectively. Acromial spur, GTA, CSA, and AI were independent risk factors for bursal-sided PTRCTs. Furthermore, CSA was the most powerful predictor of bursal-sided PTRCTs compared to GTA and AI.

Tissue-Engineered Constructions for the Needs of Cardiovascular Surgery: Possibilities of Personalization and Prospects for Use (Problem Article)

In the market for products for the needs of cardiovascular surgery, there is still no effective vascular prosthesis with a diameter of less than 4 mm, despite the continuous increase in the incidence of atherosclerosis and the increase in the number of surgical operations to restore blood flow in the affected arteries. At the same time, vascular tissue engineering has diverse methodological approaches for the development of effective functionally active small-diameter vascular prostheses suitable for adaptive growth and regeneration in situ. An important aspect is the possibility of personalizing the created prostheses not only by taking into account the individual anatomy of the patients vascular bed, but also by using autologous components to create such a prosthesis, which can be obtained directly from the recipient. The presented problematic article reflects the main results on the creation of biodegradable vascular prostheses of small diameter, obtained at the Research Institute of the Research institute for complex issues of cardiovascular diseases (Kemerovo). The functionality of the prostheses was provided both through the incorporation of biologically active components with proangiogenic potential for the purpose of complete remodeling in situ, and the formation of cell-populated vascular prostheses using autologous cells and proteins from patients with coronary heart disease. In the future, these vascular prostheses can cover the clinical need for elective and emergency cardiovascular surgery, neuro- and microsurgery, and military field vascular surgery.

Personalization of human body models and beyond via image registration.

Finite element human body models (HBMs) are becoming increasingly important numerical tools for traffic safety. Developing a validated and reliable HBM from the start requires integrated efforts and continues to be a challenging task. Mesh morphing is an efficient technique to generate personalized HBMs accounting for individual anatomy once a baseline model has been developed. This study presents a new image registration-based mesh morphing method to generate personalized HBMs. The method is demonstrated by morphing four baseline HBMs (SAFER, THUMS, and VIVA+ in both seated and standing postures) into ten subjects with varying heights, body mass indices (BMIs), and sex. The resulting personalized HBMs show comparable element quality to the baseline models. This method enables the comparison of HBMs by morphing them into the same subject, eliminating geometric differences. The method also shows superior geometry correction capabilities, which facilitates converting a seated HBM to a standing one, combined with additional positioning tools. Furthermore, this method can be extended to personalize other models, and the feasibility of morphing vehicle models has been illustrated. In conclusion, this new image registration-based mesh morphing method allows rapid and robust personalization of HBMs, facilitating personalized simulations.

A CARDIAC MOTION MODEL TO EVALUATE INTRA-FRACTION DOSIMETRIC VARIATIONS IN RADIOTHERAPY TREATMENTS

Purpose: A cardiac cycle model was implemented to simulate cardiac motion during radiotherapy to evaluate the intra-fraction dosimetric impact on cardiac sub-structures comparing different planning techniques. Methods: Cardiac sub-structures were automatically contoured in 10 CTs acquired in deep inspiration breath hold (DIBH) by using a recently developed hierarchical-clustering atlas-based algorithm. A deformable image registration algorithm was used to simulate the cardiac motion cycle based on volume variations available in the literature. Two synthetic CTs were created and contoured simulating contraction and expansion during the cardiac cycle. Ninety radiotherapy plans were calculated using three radiotherapy paradigms: tangential fields planned as Linac-3D-CRT with a steep linear dose gradient toward the heart-modulated therapy with an intermediately steep concave gradient of intermediate-to-high doses toward the heart, planned as Linac-VMAT; modulated therapy with a steep concave gradient of intermediate-to-high doses toward the heart, planned as helical tomotherapy. Python scripts were developed for autocontouring, automatic creation of synthetic CTs and data extraction. Results: Comparison between paradigms shows that different constraints (maximal gradient toward heart/lung versus maximal sparing of contralateral breast/axilla) do not necessarily result in preferred or reduced heart sparing, but this depends more on individual anatomy. A planning paradigm with an intermediate-steepness dose gradient showed the best robustness against intra-fraction organ motion. Conclusions: Patient-specific organ motion models may reduce differences between planned and delivered RT and may thus help to refine dose–volume–toxicity models for cardiac sub-structures and, as a consequence, clinical constraints. Automatized plan recalculation on synthetic image sets might be used for robustness optimization and evaluation.

Evolution of Concepts: Can Personalized Hip Arthroplasty Improve Joint Stability?

Hip arthroplasty procedures are successful and reproducible. However, within the first two post-operative years, hip dislocations are the most common cause for revisions. This is despite the majority of the dislocations having the acetabular component within what is described as the 'safe zone'. The limitations of such boundaries do not take into account the variability of individual hip anatomy and functional pelvic orientation that exist. An alternative concept to address hip instability and improve overall outcomes is functional acetabular orientation. In this review article, we discuss the evolution of concepts, particularly the kinematic alignment technique for hip arthroplasty and the use of large-diameter heads to understand why total hip arthroplasty dislocations occur and how to prevent them.

PO-04-027 A DAUNTING ASCENT: MAKING THE DIFFICULT CLIMB TO THE LEFT VENTRICULAR SUMMIT

Premature ventricular contractions (PVCs) originating from the left ventricular (LV) summit continue to be a challenging target for operators mainly due to inaccessibility. Alternate vantage points for PVC ablation should be explored. We describe two cases of LV summit PVCs presenting with inaccessible targets, necessitating different endocardial vantage points and strategies for successful ablation. N/A A 61-year-old woman presented from an outside medical facility. Despite a prior PVC ablation and use of antiarrhythmics, she was still experiencing symptomatic frequent PVCs (26% burden) along with a PVC (left bundle branch morphology with transition between V2 to V3, pseudo-delta wave, inferior axis) induced cardiomyopathy. This PVC was mapped with a high density mapping catheter in the right ventricular outflow tract (RVOT), left ventricular outflow tract (LVOT) and coronary sinus (CS) with a 2mm multi-polar catheter. Fractionated electrograms (EGMs) were detected at -52msec pre-QRS from the LV summit. The RVOT and LVOT were not early. Even though the LVOT site was not early, we were able to get our closest endocardial vantage point opposite to the earliest site, inferior to the left coronary cusp where successful ablation was achieved. In our second case, a 16-year-old male presented with symptomatic frequent PVCs (right bundle branch morphology and small R wave in V1, inferiorly directed) with high burden (26%). This PVC was mapped initially in the RVOT and LVOT. The LVOT EGM was -20msec pre-QRS but ablation at this site did not eliminate the PVC. Further mapping with our 2mm multi-polar catheter into the CS and its venous branches showed the earliest EGM of -28msec pre-QRS at the LV summit. Due to tortuosity of the venous system, our ablation catheter was not able to be driven at this site. Further mapping beyond the RVOT into the left pulmonary artery vantage point showed only -20msec pre-QRS (97% pace map match) just opposite to the LV summit. Ablation at this vantage point was successful due to spatial proximity to the LV summit. Despite innovations in ablative techniques operators are still in need of novel ablation maneuvers. Mapping catheters and ablation systems are limited in their utility by individual anatomy, necessitating exploration of alternative vantage points. Our cases highlight two instances where, despite not being earliest to the clinical PVC, a different vantage point with spatial proximity to the LV summit led to successful ablation.

PO-04-158 INTRACARDIAC ECHOCARDIOGRAPHY GUIDES ANATOMICAL ISTHMUS ABLATION IN PATIENTS WITH VENTRICULAR TACHYCARDIA AND REPAIRED TETRALOGY OF FALLOT

Successful catheter ablation of monomorphic ventricular tachycardia (VT) in patients with repaired Tetralogy of Fallot (TOF) can be achieved by targeting one or more of four common anatomical isthmuses. However, variability in the size and location of surgical patches means careful mapping is required to design ablation lines to block the critical isthmus. Intracardiac echocardiography (ICE) may assist ablation by accurate identification of individual TOF anatomy. To determine whether the routine use of ICE aids linear ablation of VT isthmuses in patients with repaired TOF. Retrospective study of repaired TOF patients undergoing VT ablation at our centre from January 2017 to November 2022. Cases were divided into those which used ICE to assist anatomical mapping versus those which used voltage mapping to identify patches and valve annuli. Once anatomy was defined, we started with a VT stimulation study where haemodynamically stable VTs were mapped. Non-inducible or unstable VTs underwent substrate mapping in sinus rhythm. All cases underwent ablation and had no inducible monomorphic VT as the endpoint. Data are presented as median and [interquartile range]. Twenty-six patients were identified, of which 15 were guided by ICE. The baseline demographic data is presented in the table and a representative figure shows the use of ICE to identify surgical patches. The use of ICE allowed linear ablation of the critical anatomical isthmus in 12/15 patients (80%) compared to 4/11 (36%) without ICE (p=0.023). The remaining patients without linear ablation underwent substrate-based ablation only to sites of local abnormal ventricular activity. There was no significant difference in overall procedure time (ICE: 165 [60] minutes versus no ICE: 145 [50] minutes; p=0.24), nor in fluoroscopy time (ICE: 25 [17] minutes versus no ICE: 31 [16] minutes; p=0.9). Over time, the introduction of ICE was associated with improved workflow. When comparing the first and last five cases using ICE, both median procedure times (from 196 to 160 minutes) and fluoroscopy times (from 35 to 20 minutes) were shorter. Intracardiac echocardiography improves targeted linear ablation of the critical anatomical isthmus for VT in patients with repaired TOF. ICE provides real-time individualised identification of surgical patches and valve anatomy to guide optimal linear lesion sets across isthmuses, with routine use over time showing a trend towards shorter procedural and fluoroscopy times.Tabled 1Baseline demographicsICE (n=15)No ICE (n=11)Age (years)53 [26]41 [23]Male10 (67%)7 (64%)Number of sternotomies2 [1]3 [2]History of syncope5 (33%)1 (9%)QRS width (milliseconds)176 [59]172 [54]Left ventricular ejection fraction (%)50 [25]54 [9]Right ventricular ejection fraction (%)29 [8]27 [7]Implantable cardiac defibrillator7 (47%)5 (45%)History of sustained VT12 (80%)8 (73%)VT ablation15 (100%)11 (100%)Inducible VT at electrophysiology study11 (73%)6 (55%)Linear anatomical isthmus ablation12 (80%)4 (36%)Procedure time (minutes)165 [60]145 [50]Fluoroscopy time (minutes)25 [17]31 [16] Open table in a new tab

Double-Bundle Anterior Cruciate Ligament Reconstruction With Primary Repair and Hamstring Autograft Augmentation

The optimal treatment of a ruptured anterior cruciate ligament (ACL) restores the patient’s native anatomy and biomechanics as close to normal as possible. The purpose of this technical note is to describe an ACL reconstruction technique in which a double-bundle concept is used, wherein one bundle contains repaired ACL tissue and the second bundle contains a hamstring autograft, and each bundle is tensioned independently. Even in chronic cases, this technique allows for incorporation of the native ACL because, more often than not, there is sufficient tissue of good quality available for repair of one bundle. By augmenting the ACL repair with an autograft sized to the fit the individual anatomy, the patient’s ACL tibial footprint can be closely restored to normal, and the potential benefits of tissue preservation are combined with the biomechanical strengths of an autograft double-bundle ACL reconstruction.

Effective networks mediate right hemispheric dominance of human 40 Hz auditory steady-state response.

Auditory steady-state responses (ASSR) are induced from the brainstem to the neocortex when humans hear periodic amplitude-modulated tonal signals. ASSRs have been argued to be a key marker of auditory temporal processing and pathological reorganization of ASSR – a biomarker of neurodegenerative disorders. However, most of the earlier studies reporting the neural basis of ASSRs were focused on looking at individual brain regions. Here, we seek to characterize the large-scale directed information flow among cortical sources of ASSR entrained by 40 Hz external signals. Entrained brain rhythms with power peaking at 40 Hz were generated using both monaural and binaural tonal stimulation. First, we confirm the presence of ASSRs and their well-known right hemispheric dominance during binaural and both monaural conditions. Thereafter, reconstruction of source activity employing individual anatomy of the participant and subsequent network analysis revealed that while the sources are common among different stimulation conditions, differential levels of source activation and differential patterns of directed information flow among sources underlie processing of binaurally and monaurally presented tones. Particularly, we show bidirectional interactions involving the right superior temporal gyrus and inferior frontal gyrus underlie right hemispheric dominance of 40 Hz ASSR during both monaural and binaural conditions. On the other hand, for monaural conditions, the strength of inter-hemispheric flow from left primary auditory areas to right superior temporal areas followed a pattern that comply with the generally observed contralateral dominance of sensory signal processing.

V09-03 GENDER-AFFIRMING CLITOROPLASTY: TWO VERSIONS AND RATIONALE FOR CHOICE

You have accessJournal of UrologyCME1 Apr 2023V09-03 GENDER-AFFIRMING CLITOROPLASTY: TWO VERSIONS AND RATIONALE FOR CHOICE Michele Fascelli, Geolani Dy, Blair Peters, and Daniel Dugi Michele FascelliMichele Fascelli More articles by this author , Geolani DyGeolani Dy More articles by this author , Blair PetersBlair Peters More articles by this author , and Daniel DugiDaniel Dugi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003317.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: We present two techniques for creating the neoclitoris in gender-affirming vaginoplasty and vulvoplasty, preputial skin flap clitoroplasty and urethral flap clitoroplasty. METHODS: The technique to be used is chosen prior to skin incision. After penile disassembly, the the glans is reconstructed to form the clitoris, based on the corona. The tissue used to construct the clitoral hood and labia minora differs by technique, and the decision to use one technique or the other is based on patient anatomy. RESULTS: We demonstrate two techniques and their post-operative results. We chose the preputial skin clitoroplasty for all uncircumcised patients and patients with adequate penile skin, both distal to and proximal to the circumcision scar. We chose the urethral flap clitoroplasty technique for circumcised patients with penile skin insufficient for the preputial skin technique. CONCLUSIONS: These two techniques for clitoroplasty provide surgical options adaptable to individual anatomy. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e837 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Michele Fascelli More articles by this author Geolani Dy More articles by this author Blair Peters More articles by this author Daniel Dugi More articles by this author Expand All Advertisement PDF downloadLoading ...

Reduction of spondylolisthesis and restoration of lumbar lordosis after anterior lumbar interbody fusion (ALIF)

BackgroundAnterior lumbar interbody fusion (ALIF) is a well-established surgical treatment option for various diseases of the lumbar spine, including spondylolisthesis. This study aimed to evaluate the postoperative correction of spondylolisthesis and restoration of lumbar and segmental lordosis after ALIF.MethodsPatients with spondylolisthesis who underwent ALIF between 2013 and 2019 were retrospectively assessed. We assessed the following parameters pre-and postoperatively (6-months follow-up): Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), lumbar lordosis (LL), segmental lordosis (SL), L4/S1 lordosis, and degree of spondylolisthesis.Results96 patients were included. In 84 cases (87.50%), additional dorsal instrumentation was performed. The most frequent diagnosis was isthmic spondylolisthesis (73.96%). VAS was reduced postoperatively, from 70 to 40, as was ODI (50% to 32%). LL increased from 59.15° to 64.45°, as did SL (18.95° to 28.55°) and L4/S1 lordosis (37.90° to 44.00°). Preoperative spondylolisthesis was 8.90 mm and was reduced to 6.05 mm postoperatively. Relative spondylolisthesis was 21.63% preoperatively and 13.71% postoperatively. All clinical and radiological improvements were significant (all p < 0.001). No significant difference considering the lordosis values nor spondylolisthesis was found between patients who underwent ALIF surgery without dorsal instrumentation and patients who received additional dorsal instrumentation. Venous laceration was the most frequent complication (10.42%).ConclusionsWith ALIF, good clinical results and safe and effective reduction of spondylolisthesis and restoration of lordosis can be achieved. Additional dorsal instrumentation does not significantly affect postoperative lordosis or spondylolisthesis. Individual vascular anatomy must be reviewed preoperatively before considering ALIF.

Virtual pterygoid implant planning in maxillary atrophic patients: prosthetic-driven planning and evaluation

PurposeThe study aims to use cone beam computed tomography (CBCT) to (1) define the virtual valid length of pterygoid implants in maxillary atrophic patients from the prosthetic prioritized driven position and (2) measure the implant length engaged in the pterygoid process according to the HU difference of the pterygoid maxillary junction.Materials and methodsVirtual pterygoid implants were planned with CBCT of maxillary atrophic patients in the software. The entry and angulation of the implant were planned according to the prosthetic prioritized driven position in the 3D reconstruction image. The planned implant length and the valid length defined as the implant between the pterygoid maxillary junction and pterygoid fossa were recorded. The relationship between the implant and sinus cavity was also evaluated.ResultsA total of 120 CBCT samples were enrolled and virtually planned. The mean age of the patients was 56.2 ± 13.2 years. One hundred and sixteen samples could successfully place virtual implants according to the criterion. The mean implant length and mean implant length beyond the pterygoid maxillary junction were 16.3 ± 4.2 mm (range, 11.5–18 mm) and 7.1 ± 3.3 mm (range, 1.5–11.4 mm), respectively. Ninety percent of virtually planned implants had a close relationship with the sinus cavity, and implants exhibited longer lengths when they had no relation with the sinus.ConclusionFrom a prosthetic prioritized driven position with fixed entry and angulation, pterygoid implants achieve adequate bone anchorage length beyond the pterygoid maxillary junction. Due to the individual anatomy and the volume of the maxillary sinus, the implants presented a different positional relationship with the maxillary sinus.Graphical

Local design and manufacturing of patient-specific implant using Anatomage Medical Design Studio software: proof of concept - Botswana’s 1st case report

BackgroundBotswana, like most sub-Sahara African nations, uses conventional orthopaedic implants that are sourced from major manufactures in the West. The implants are mass-produced and designed with universal configurations to fit an average patient. During surgery, surgeons thus sometimes bend the implants to match the individual bone anatomy, especially for paediatric patients and those with unique deformities, thus risking implant failure. The purpose of this project was to show the feasibility of developing safe and effective patient-specific orthopaedic implants in a low-resourced market.MethodsCT Scan slice files of a paediatric patient with Ollier’s disease were used to reconstruct the lower limb anatomy. The resultant files were 3D printed into prototypes that showed severe right knee valgus deformity. The surgeon used the prototype to plan for corrective femoral osteotomy and the required implant. The implant design and planned surgery were subsequently simulated on the Medical Design Studio software for proper fitting before final implant printing. Surgery was then performed, followed by 12 weeks of physiotherapy.ResultsPost-surgical x-rays demonstrated good implant positioning and knee joint alignment. At 18 months of post-surgical follow-up, the child was pain-free, could perform full squats, and ambulation was near-normal, without the use of an assistive device.ConclusionsIt is feasible to develop effective, patient-specific implants for selected orthopaedic cases in a low-resourced country. This work could improve surgical and rehabilitation outcomes for selected paediatric patients and those with severe bone deformities.

Cinematic versus volume rendered imaging for the depiction of complex congenital heart disease.

Planning for surgical intervention for patients with complex congenital heart disease requires a comprehensive understanding of the individual's anatomy. Cinematic rendering (CR) is a novel technique that purportedly builds on traditional volume rendering (VR) by converting CT image data into clearly defined 3D reconstructions through the stimulation and propagation of light rays. The purpose of this study was to compare CR to VR for the understanding of critical anatomy in unoperated complex congenital heart disease. In this retrospective study, CT data sets from 20 sequential scanned cases of unoperated paediatric patients with complex congenital heart disease were included. 3D images were produced at standardised and selected orientations, matched for both VR and CR. The images were then independently reviewed by two cardiologists, two radiologists and two surgeons for overall image quality, depth perception and the visualisation of surgically relevant anatomy, the coronary arteries and the pulmonary veins. Cinematic rendering demonstrated significantly superior image quality, depth perception and visualisation of surgically relevant anatomy than VR. Cinematic rendering is a novel 3D CT-rendering technique that may surpass the traditionally used volumetric rendering technique in the provision of actionable pre-operative anatomical detail for complex congenital heart disease.

Numerical simulations for characterization of missing articulatory information in ultrasound imaging of speech

The air–tissue interface at the tongue surface allows submental (below the chin) B-mode ultrasound images to depict the shape of the tongue in real time, useful for measuring and understanding typical and disordered tongue articulation during speech production. However, parts of the tongue are obscured; depending on an individual speaker's anatomy and tongue movement patterns, the anterior tongue tip may be shadowed by the mandible bone and the sublingual airspace. To characterize this missing information about the tongue tip in ultrasound images, midsagittal ultrasound images were numericallysimulated. Three-dimensional anatomic models were constructed using magnetic resonance imaging (MRI) data to map tongue tissue, surrounding air, and an estimated position of the mandible. Pulse-echo ultrasound images were then numerically simulated using the open-source k-Wave toolbox. Acoustic properties of the medium and an imaging array model are identified that allow simulations to replicate features in ultrasound images recorded from the same speakers as the MRI data, while maintaining computational efficiency. The potential to recover missing information on the tongue tip position from reverberation artifacts is assessed.