Evaluation of finite element modeling methods for predicting compression screw failure in a custom pelvic implant.

Introduction: Three-dimensional (3D)-printed custom pelvic implants have become a clinically viable option for patients undergoing pelvic cancer surgery with resection of the hip joint. However, increased clinical utilization has also necessitated improved implant durability, especially with regard to the compression screws used to secure the implant to remaining pelvic bone. This study evaluated six different finite element (FE) screw modeling methods for predicting compression screw pullout and fatigue failure in a custom pelvic implant secured to bone using nine compression screws. Methods: Three modeling methods (tied constraints (TIE), bolt load with constant force (BL-CF), and bolt load with constant length (BL-CL)) generated screw axial forces using functionality built into Abaqus FE software; while the remaining three modeling methods (isotropic pseudo-thermal field (ISO), orthotropic pseudo-thermal field (ORT), and equal-and-opposite force field (FOR)) generated screw axial forces using iterative physics-based relationships that can be implemented in any FE software. The ability of all six modeling methods to match specified screw pretension forces and predict screw pullout and fatigue failure was evaluated using an FE model of a custom pelvic implant with total hip replacement. The applied hip contact forces in the FE model were estimated at two locations in a gait cycle. For each of the nine screws in the custom implant FE model, likelihood of screw pullout failure was predicted using maximum screw axial force, while likelihood of screw fatigue failure was predicted using maximum von Mises stress. Results: The three iterative physics-based modeling methods and the non-iterative Abaqus BL-CL method produced nearly identical predictions for likelihood of screw pullout and fatigue failure, while the other two built-in Abaqus modeling methods yielded vastly different predictions. However, the Abaqus BL-CL method required the least computation time, largely because an iterative process was not needed to induce specified screw pretension forces. Of the three iterative methods, FOR required the fewest iterations and thus the least computation time. Discussion: These findings suggest that the BL-CL screw modeling method is the best option when Abaqus is used for predicting screw pullout and fatigue failure in custom pelvis prostheses, while the iterative physics-based FOR method is the best option if FE software other than Abaqus is used.

Enhancing Retention in Digit Rehabilitation: Implant-Assisted Silicone Finger Prosthesis for an Amputated Thumb.

This case report details the prosthetic replacement of a thumb lost due to traumatic amputation. The primary goal of this replacement was to restore the thumb's functionality, enabling the patient to resume daily activities such as writing and holding objects. A silicone prosthesis, anchored by an osseointegrated implant in the metacarpal bone, was used for this purpose. In this instance, a young female's thumb stump was functionally rehabilitated with the assistance of bone-anchored implants and room-temperature-vulcanizing silicones. At the follow-up appointment, no complications were observed, and the prosthesis remained in excellent condition, requiring no additional intervention. Utilizing bone-anchored implants to enhance retention in short stumps post-amputation proves to be one of the most effective methods to restore function and improve the daily lives of such patients.

Learning curves for high tibial osteotomy using patient-specific instrumentation: a case control study.

Objectives: Three-dimensional (3D) planning and Patient Specific Instrumentation (PSI) can help the surgeon to obtain more predictable results in Medial Opening Wedge High Tibial Osteotomy (mOW-HTO) than the conventional techniques. We compared the accuracy of the PSI and standard techniques and measured the learning curve for surgery time and number of fluoroscopic shots. Methods: We included the first 12 consecutive cases of mOW-HTO performed with 3D planning and PSI cutting guides and the first 12 non-supervised mOW-HTO performed with the standard technique. We recorded surgery time and fluoroscopic time. We calculated the variation (Δ delta) between the planned target and the postoperative result for Hip Knee Ankle Angle (HKA), mechanical medial Proximal Tibia Angle (MPTA), Joint Line Convergence Angle (JLCA) and tibial slope (TS) and compared it both groups. We also recorded the complication rate. We then calculated the learning curves for surgery time, number of fluoroscopic shots, Δ from target in both groups. CUSUM analysis charts for learning curves were applied between the two groups. Results: Mean surgical time and mean number of fluoroscopic shots were lower in PSI group (48.58±7.87 vs. 58.75±6.86 min; p=0.034 and 10.75±3.93 vs. 18.16±4.93 shots; p<0.001). The postoperative ΔHKA was 0.42±0.51° in PSI vs. 1.25±0.87° in conventional, p=0.005. ΔMPTA was 0.50±0.67° in PSI vs. 3.75±1.48° in conventional, p<0.001; ΔTS was 1.00±0.82° in PSI vs. 3.50±1.57° in conventional, p<0.001. ΔJLCA was 1.83±1.11° in PSI vs. 4±1.41° in conventional, p<0.001. The CUSUM analysis favoured PSI group regarding surgery time (p=0.034) and number of shots (p<0.001) with no learning curve effect for ΔHKA, ΔMPTA, ΔJLCA and ΔTS. Conclusions: PSI cutting guides and 3D planning for HTO are effective in reducing the learning curves for operation time and number of fluoroscopic shots. Accuracy of the procedure has been elevated since the first cases.

Computational imaging for rapid detection of grade-I cerebral small vessel disease (cSVD).

An early identification and subsequent management of cerebral small vessel disease (cSVD) grade 1 can delay progression into grades II and III. Machine learning algorithms have shown considerable promise in medical image interpretation automation. An experimental cross-sectional study aimed to develop an automated computer-aided diagnostic system based on AI (artificial intelligence) tools to detect grade 1-cSVD with improved accuracy. Patients with Fazekas grade 1 cSVD on Non-Contrast Magnetic Resonance Imaging (MRI) Brain of age >40 years of both genders were included. The dataset was pre-processed to be fed into a 3D convolutional neural network (CNN) model. A 3D stack with the shape (120, 128, 128, 1) containing axial slices from the brain magnetic resonance image was created. The model was created from scratch and contained four convolutional and three fully connected (FC) layers. The dataset was preprocessed by making a 3D stack, and normalizing, resizing, and completing the stack was performed. A 3D-CNN model architecture was designed to train and test preprocessed images. We achieved an accuracy of 93.12 % when 2D axial slices were used. When the 2D slices of a patient were stacked to form a 3D image, an accuracy of 85.71 % was achieved on the test set. Overall, the 3D-CNN model performed very well on the test set. The earliest and the most accurate diagnosis from computational imaging methods can help reduce the huge burden of cSVD and its associated morbidity in the form of vascular dementia.

Club Foot with Contralateral Congenital Amniotic Band Syndrome Amputation Successfully Treated with Ponseti Method: Case Report.

Introduction: Constriction amniotic band syndrome (CABS) is a rare condition associated with the fibrous amniotic bands that restrict and ensnare the fetus in utero resulting in malformations at birth in one per around 15,000 live births. CABS associated with clubfoot, historically required extensive soft-tissue release due to its propensity for relapse. Case Report: A 2-day-old Caucasian male infant born at 27 weeks gestation through emergency cesarean section due to concern for placental abruption and premature rupture of membranes in the setting of a prenatal history significant for oligohydramnios. The patient presented with non-viable tissue in the right leg requiring amputation with a left-sided clubfoot deformity. Following amputation of the right leg, the clubfoot was corrected with Ponseti method of serial casting and Achilles tenotomy. Three-week post-tenotomy and 6 months of age, a custom fit prosthesis of the right leg allowed for the application of a left abduction foot orthosis which maintained the correction. Conclusion: This case study supports recent literature that CABS-associated clubfoot can be corrected with the Ponseti method. While a contralateral amputation can prevent the use of a traditional bilateral abduction foot orthosis, a custom fitted prosthesis can allow for its use and prevention of a relapse of deformity.

Custom GPTs Enhancing Performance and Evidence Compared with GPT-3.5, GPT-4, and GPT-4o? A Study on the Emergency Medicine Specialist Examination.

Given the widespread application of ChatGPT, we aim to evaluate its proficiency in the emergency medicine specialty written examination. Additionally, we compare the performance of GPT-3.5, GPT-4, GPTs, and GPT-4o. The research seeks to ascertain whether custom GPTs possess the essential capabilities and access to knowledge bases necessary for providing accurate information, and to explore the effectiveness and potential of personalized knowledge bases in supporting the education of medical residents. We evaluated the performance of ChatGPT-3.5, GPT-4, custom GPTs, and GPT-4o on the Emergency Medicine Specialist Examination in Taiwan. Two hundred single-choice exam questions were provided to these AI models, and their responses were recorded. Correct rates were compared among the four models, and the McNemar test was applied to paired model data to determine if there were significant changes in performance. Out of 200 questions, GPT-3.5, GPT-4, custom GPTs, and GPT-4o correctly answered 77, 105, 119, and 138 questions, respectively. GPT-4o demonstrated the highest performance, significantly better than GPT-4, which, in turn, outperformed GPT-3.5, while custom GPTs exhibited superior performance compared to GPT-4 but inferior performance compared to GPT-4o, with all p < 0.05. In the emergency medicine specialty written exam, our findings highlight the value and potential of large language models (LLMs), and highlight their strengths and limitations, especially in question types and image-inclusion capabilities. Not only do GPT-4o and custom GPTs facilitate exam preparation, but they also elevate the evidence level in responses and source accuracy, demonstrating significant potential to transform educational frameworks and clinical practices in medicine.

Personalized Temporomandibular Joint Total Alloplastic Replacement as a Solution to Help Patients with Non-Osteosynthesizable Comminuted Mandibular Head Fractures.

Background: Treatment methods for mandibular head fractures are controversial, although effective techniques for open reduction and rigid fixation (ORIF) have been known since the late 1990s. Notably, some forms of posttraumatic comminution of the mandibular head can be reduced or fixed. Methods: This study presents a personalized treatment to cure patients with nonreduced comminuted fractures of the mandibular head: total temporomandibular joint alloplastic replacement (18 patients). The reference group included patients who underwent ORIF (11 patients). Results: Personalized alloplastic joint replacements resulted in a more stable mandibular ramus after three months compared with ORIF. Conclusions: The authors recommend not performing osteosynthesis when the height of the mandibular ramus cannot be stably restored or when periosteal elevation from most of the mandibular head is necessary for ORIF. Personalized TMJ replacement should be considered in such patients. Personalized medicine allows patients to maintain a normal mandibular ramus height for a long period of time.

Immediate Effects of Custom Foot Orthoses on Postural Balance and Pain in Obese Middle-Aged Women With Plantar Fasciitis.

Given the prevalence of plantar fasciitis (PF) among middle-aged women, we investigated the immediate impact of custom foot orthoses (CFO) on pain and static and dynamic postural balance, addressing a critical gap in understanding the potential benefits of CFO in managing PF-related pain and postural instability. Nine middle-aged women with PF and obesity were evaluated for pain levels and center of pressure (CoP) values in bipedal, unipedal with a non-affected foot, and unipedal with an affected foot on the Timed Up and Go (TUG) test, while they were barefoot, wearing standard insoles (SI), and wearing CFO. We found that CFO significantly and immediately reduced pain (p < .01) improved CoP values (p < .01) in the unipedal stance with the affected foot, and enhanced TUG test scores (p < .001). The results demonstrated a significant (p < .01) improvement in CoParea values and TUG test scores with CFO, compared to SI. These findings underscore the immediate benefits of CFO in alleviating pain and improving postural balance in obese middle-aged women with PF, highlighting their potential as a valuable intervention.

Investigation of the effectiveness of preoperative intubation simulation using a custom-made simulator for pediatric patients with difficult airway: a pilot study.

The purpose of this study is to investigate whether preoperative intubation simulation using custom-made simulator is useful during anesthesia induction for the children who have difficult airway. We included the children under 15 years of age who have difficult airway which had been already known. Prior to the scheduled surgery, CT imaging was performed and a 3D reconstruction of the face from the chest was performed. Then custom-made airway simulator was made. We tried to intubate custom-made simulator of patients preoperatively. We planned how to intubate the patient for anesthesia induction from the result of intubation simulation. The findings of direct laryngoscopy were compared with the findings during intubation. Three patients were included in this study. It took up to 3 weeks to create a simulator, which was difficult due to time constraints to accommodate emergency surgeries. Simulation findings correlated well with findings during anesthesia induction. There were no cases of severe hypotension or hypoxia during induction of anesthesia with the planned intubation method. In conclusion, preoperative intubation simulation using custom-made simulator may be useful for the patients who have difficult airway.

Discovering the barriers to scaling a co-design approach for the provision of custom assistive technology within healthcare services.

Introduction: Using computer-aided design and 3D printing within a co-design process to produce assistive technology (AT) has a positive impact in delivering customised solutions to end-users' needs. However, to date its adoption within healthcare services has been limited. This work aims to gather clinicians' insights to identify and analyse barriers inherent in the AT design, manufacturing, and provision processes and inform a detailed understanding of the current AT eco-system. It forms part of a long-term ambition to efficiently scale up a service for the co-design of custom AT across specialties and healthcare services.Methods: Five interactive workshops were run with 21 healthcare professionals currently involved in AT provision. Participants were recruited from two health boards in the UK. Thematic analysis was used to identify common barriers to scaling up a custom AT approach. Additionally, an eco-system map was created to determine the key stakeholders and their interactions.Results: Nineteen descriptive themes, grouped into four analytical themes, were identified related to the design of AT, access to AT, healthcare staffing and healthcare system pressures. The eco-system map identified sixteen individual stakeholders and ten different groups of significant corporate stakeholders.Discussion: The identified barriers relate to both the provision of off-the-shelf and the co-design of customised AT. Further promoting the scaling up of a co-design custom AT process requires: improving communication between stakeholders, enabling information about AT to be easily accessible, ensuring feedback is gathered and used, and creating tools that enable non-expert designers to modify custom AT designs safely and effectively.

The provision of custom assistive technology (AT) needs to centre around engaging end-users from the outset to set goals, manage expectations and educate individuals on the solutions available.A digital platform needs to be developed that incorporates a user-friendly repository with clear information about off-the-shelf and custom AT solutions available.The platform should facilitate easy communication between healthcare services and the end-users of AT and enable feedback to be easily gathered and shared.The scaling up of co-design processes for the provision of custom AT within healthcare services requires training of non-expert designers in digital design and manufacturing and the creation of more user-friendly computer aided design tools.

Survivorship analysis of CAD-CAM total shoulder replacement.

Background: Glenoid bone loss represents a challenge in shoulder arthroplasty and often precludes standard implants. The CAD-CAM total shoulder replacement (TSR) is an option in these cases. This study aimed to assess survivorship and long-term patient outcomes of the CAD-CAM TSR. Methods: Fifty-eight patients that underwent a CAD-CAM TSR by three surgeons at a single tertiary referral centre between 2009 and 2017 were reviewed. The mean follow-up was 70 months (28-130). Data was collected on survivorship, range of movement, Oxford shoulder score (OSS, 0-48), subjective shoulder value (SSV, 0-100%), pain score (0-10), and overall patient satisfaction. Results: CAD-CAM TSR was undertaken as a primary procedure in 28% (n = 16) for end-stage arthritis with severe glenoid bone loss, and as a revision procedure in 72% (n = 42). Of the total, 17% (n = 10) required component revision at a mean of 24 months (4x prosthesis loosening, 3x infection, 3x periprosthetic fracture). Forward elevation improved from 45° ± 27° to 59° ± 29° (P = 0.0056), abduction from 43° ± 29° to 55° ± 26° (P = 0.034) and external rotation from 8° ± 11° to 16° ± 14° (P = 0.031). OSS improved from 15 ± 8 to 29 ± 9 (P = 0.0009), SSV from 18 ± 16 to 62 ± 23 (P < 0.0001), and pain score from 8 ± 2 to 2 ± 2 (P < 0.0001). 88% of patients would undergo the procedure again. Conclusion: CAD-CAM TSR is reserved for complex cases involving severe glenoid bone loss, offering significant improvements in pain and function with overall positive patient satisfaction.

Data from steady-state simulation and economic evaluation in the power to methane context for synthetic natural gas production and power generation.

The data presented in this article is generated by a steady-state simulation for performing a techno-economic assessment for comparing three electrolysis technologies in the PtM context. The data is focused on two aspects. First, the description of the steady-state simulation of six PtM systems modeled using Aspen Custom Modeler (ACM) and Aspen Plus (AP). Second, an economic assessment is carried out for each of the mentioned PtM systems to compare the feasibility, the profitability and performance of these systems on a larger scale to produce synthetic natural gas, power generation and carbon utilization given in the main research article. Three electrolysis technologies (namely Alkaline Electrolysis - AE, Proton Exchange Membrane Electrolysis - PEME and Solid Oxide Electrolysis - SOE) were modeled having in mind two methane applications: a combined cycle for power generation and the syngas generation. In addition, on each PtM system is carried out an economic evaluation by calculating fixed capital investment (FCI) and manufacturing costs (MC).

Advancements in the Ocular Prosthesis Technology: The Insightful Innovations.

In patients who have lost their eye due to one or many of the following events, such as surgery, trauma, tumors, or birth eye defects, ocular prostheses play a very vital role in the recovery of their eye appearance and social appearance. This case report highlights the successful fitting and fabrication of a custom-made ocular prosthesis in a patient with an eye defect. The manufacturing process of the prostheses involved careful evaluation and fabrication involving a series of steps to achieve a successful prosthesis. A customized prosthesis guarantees excellent esthetic matching, more comfort, and increased patient confidence, thereby a better quality of life.

Fabrication of a Customized Ocular Prosthesis: A Case Report.

Orbital defects due to congenital causes, cancer, and trauma can compromise appearance and function, creating a deep psychological impact on an individual's life. The prosthetic rehabilitation of such patients is challenging. The objective of prosthetic treatment of an ocular defect is to provide a well-fitting ocular prosthesis that closely resembles the original eye, restoring the patient's self-confidence and social acceptance. Ocular prostheses can be customized or prefabricated. The challenge encountered with prefabricated eye prostheses is a poor fit. Customized prostheses exhibit better fit, aesthetic outcome, and comfort to the patient in the long term. The article describes a technique to fabricate an ocular prosthesis with a stock iris and customized sclera that is both functional and aesthetically pleasing.

Exploring the Potential of Code-Free Custom GPTs in Ophthalmology: An Early Analysis of GPT Store and User-Creator Guidance.

INTRODUCTION: OpenAI recently introduced the ability to create custom generative pre-trained transformers (cGPTs) using text-based instruction and/or external documents using retrieval-augmented generation (RAG) architecture without coding knowledge. This study aimed to analyze the features of ophthalmology-related cGPTs and explore their potential utilities. METHODS: Data collection took place on January 20 and 21, 2024, and custom GPTs were found by entering ophthalmology keywords into the "Explore GPTS" section of the website. General and specific features of cGPTs were recorded, such as knowledge other than GPT-4 training data. The instruction and description sections were analyzed for compatibility using the Likert scale. We analyzed two custom GPTs with the highest Likert score in detail. We attempted to create a convincingly presented yet potentially harmful cGPT to test safety features. RESULTS: We analyzed 22 ophthalmic cGPTs, of which 55% were for general use and the most common subspecialty was glaucoma (18%). Over half (55%) contained knowledge other than GPT-4 training data. The representation of the instructions through the description was between "Moderately representative" and "Very representative" with a median Likert score of 3.5 (IQR 3.0-4.0). The instruction word count was significantly associated with Likert scores (P = 0.03). Tested cGPTs demonstrated potential for specific conversational tone, information, retrieval and combining knowledge from an uploaded source. With these safety settings, creating a malicious GPT was possible. CONCLUSIONS: This is the first study to our knowledge to examine the GPT store for a medical field. Our findings suggest that these cGPTs can be immediately implemented in practice and may offer more targeted and effective solutions compared to the standard GPT-4. However, further research is necessary to evaluate their capabilities and limitations comprehensively. The safety features currently appear to be rather limited. It may be helpful for the user to review the instruction section before using a cGPT.

Comparative Evaluation of the Short-Term Outcome of Different Endovascular Aortic Arch Procedures.

Objectives: There are several endovascular treatment options to treat aortic arch and thoracic aortic pathologies with custom-made or surgeon-modified aortic stent grafts. This study seeks to assess endovascular treatment methods for aortic arch and thoracic aortic pathologies with no acceptable proximal landing zone for standard thoracic endovascular aortic repair (TEVAR), comparing different treatment methods and evaluating technical success, intraoperative parameters and short-term outcomes. Methods: All patients undergoing elective or emergency endovascular treatment of aortic arch and thoracic aortic pathologies, with no acceptable landing zone for standard TEVAR, between 1 January 2010 and 31 March 2024, at the University Hospital Düsseldorf, Germany were included. An acceptable landing zone was defined as a minimum of 2 cm for sufficient sealing. All patients were not suitable for open surgery. Patients were categorized by an endovascular treatment method for a comprehensive comparison of pre-, intra- and postoperative variables. IBM SPSS29 was used for data analysis. Results: The patient cohort comprised 21 patients, predominantly males (81%), with an average age of 70.9 ± 9 years with no acceptable proximal landing zone for standard TEVAR procedure. The most treated aortic pathologies were penetrating aortic ulcers and chronic post-dissection aneurysms. Patients were sub-grouped according to the applied procedure as follows: five patients with chimney thoracic endovascular aortic repair (chTEVAR), seven patients with in situ fenestrated thoracic endovascular aortic repair (isfTEVAR), six patients with custom-made fenestrated thoracic endovascular aortic repair (cmfTEVAR) and three patients with custom-made branched thoracic endovascular aortic repair (cmbTEVAR). Emergency procedures involved two patients. There were significant differences in the total procedure and fluoroscopy time, as well as in contrast agent usage among the treatment groups. cmfTEVAR had the shortest total procedure time, while chTEVAR exhibited the highest contrast agent usage. The overall mortality rate among all procedures was 9.5% (two patients) and 4.7% for elective procedures, respectively. Deaths were associated with either retrograde type A dissection or stent graft infection. Both patients were treated with chTEVAR. There was one minor and one major stroke; these patients were treated with isfTEVAR. No endoleak occurred during any procedure. The reintervention rate for chTEVAR was 20% and 0% for all other procedures during the in-hospital stay. The patients who were treated with cmfTEVAR had no complications, the shortest operating and fluoroscopy time, and less contrast agent was needed in comparison with other treatment methods. Conclusions: Complex endovascular procedures of the aortic arch with custom-made or surgeon-modified aortic stent grafts offer a safe solution, with acceptable complication rates for patients who are not suitable for open aortic arch repair. In terms of procedure-related parameters and complication rates, a custom-made fenestrated TEVAR is potentially advantageous compared to the other endovascular techniques.

The experiences of podiatrists prescribing custom foot orthoses and patients using custom foot orthoses for foot pain management in the United Kingdom: A focus group study.

INTRODUCTION: Foot pain can be a significant burden for patients. Custom foot orthoses (CFOs) have been a mainstay in podiatry treatment for foot pain management and improving foot function. However, little is known about podiatrists' experience of prescribing CFOs or patient experience of using foot orthoses (FOs), including CFOs, for foot pain. METHODS: A focus group (FG) discussion with three FOs users (Female = 2 and Male = 1) was conducted in November 2022 within a private podiatry practice. This group represented non-experts from the general local population of individuals with existing or previous foot pain who have personally experienced using either over-the-counter FOs or CFOs. An online FG discussion with five musculoskeletal (MSK) specialist podiatrists (Female = 2 and Male = 3) was also conducted in December 2022. This group represented podiatrists with specialist knowledge in foot biomechanics and clinical experience in CFO provision. The FG discussions were recorded and lasted 49 and 57 min respectively. Transcribed data was manually coded, and a thematic analysis was undertaken to identify patterns within the collected data. RESULTS: The participants in the patient FG detailed mixed experiences of the prescription process and CFOs received, with reports of limited involvement/input in their prescription, the need for frequent adjustments and high costs. The impact on footwear choices, replicability and transferability of CFOs into different types of shoes and technologies to aid design were also highlighted. In the podiatrist FG, lack of confidence in design and manufacture processes, prescription form language, relationship and communication building with manufacturers, variability in the CFOs issued and the need for better student education in CFO provision emerged as key themes. CONCLUSION: Patients and podiatrists shared similar views on CFO provision, namely poor communication with manufacturers leading to dissatisfaction with the CFOs prescribed causing negative impacts on patient experiences. Podiatrists called for greater education at registration level to increase new graduate podiatrist knowledge in CFO design and manufacture and better collaboration with manufacturing companies.

Radiological Landmarks for Joint Line Level in Challenging Total Ankle Arthroplasty.

Background: Although Total Ankle Arthroplasty (TAA) is primarily performed for post-traumatic ankle arthritis with joint disruption, anatomical landmarks for Joint Line (JL) level are typically preserved. However, severe Post-Traumatic Bone Loss (PTBL) or TAA revision may render some landmarks unidentifiable, challenging JL restoration. Methods: Patients undergoing customized TAA for severe PTBL or revision were enrolled. Custom-made implants, based on 3D CT scans, were designed to address bone defects and provide adequate bone support. Evaluated parameters, measured on bilateral ankle weight-bearing radiographs taken preoperatively and 6-8 months postoperatively, included JL Height Ratio (JLHR) and the distances from JL to the Lateral Malleolus apex (LM-JL), the posterior colliculus of the Medial Malleolus (MM-JL), and the Gissane Calcaneal Sulcus (CS-JL). Reproducibility and variability were assessed, and comparisons were made between radiological parameters measured at TAA and those at the contralateral ankle. Results: Thirteen patients were included. Intra- and interobserver reliability demonstrated excellent values. The least variability was observed in the LM-JL distance. Statistically significant correlations were found between CS-JL and MM-JL distances in the operated limb and between the CS-JL of the operated limb and the contralateral ankle. While TAA parameters did not show statistically significant differences compared with the contralateral ankle, a trend toward proximalization of the JL was noted. Conclusions: This study demonstrated good reproducibility of the analyzed parameters for evaluating JL in TAA among patients with severe PTBL or undergoing revision surgery. However, these parameters cannot be deemed fully reliable. Given their potential weaknesses, it is crucial to identify more reproducible values, preferably ratios.

Multi-Channel Microscale Nerve Cuffs for Spatially Selective Neuromodulation.

Peripheral nerve modulation via electrical stimulation shows promise for treating several diseases, but current approaches lack selectivity, leading to side effects. Exploring selective neuromodulation with commercially available nerve cuffs is impractical due to their high cost and limited spatial resolution. While custom cuffs reported in the literature achieve high spatial resolutions, they require specialized microfabrication equipment and significant effort to produce even a single design. This inability to rapidly and cost-effectively prototype novel cuff designs impedes research into selective neuromodulation therapies in acute studies. To address this, we developed a reproducible method to easily create multi-channel epineural nerve cuffs for selective fascicular neuromodulation. Leveraging commercial flexible printed circuit (FPC) technology, we created cuffs with high spatial resolution (50 µm) and customizable parameters like electrode size, channel count, and cuff diameter. We designed cuffs to accommodate adult mouse or rat sciatic nerves (300-1500 µm diameter). We coated the electrodes with PEDOT:PSS to improve the charge injection capacity. We demonstrated selective neuromodulation in both rats and mice, achieving preferential activation of the tibialis anterior (TA) and lateral gastrocnemius (LG) muscles. Selectivity was confirmed through micro-computed tomography (µCT) and quantified through a selectivity index. These results demonstrate the potential of this fabrication method for enabling selective neuromodulation studies while significantly reducing production time and costs compared to traditional approaches.

Next-Generation Custom-Fit Reusable Respiratory Protective Device with Continuous Fit Monitoring - Part II: Continuous Fit Monitoring.

Filtering facepiece respirators (FFRs) are manufactured in discrete sizes, with some models being limited in accommodating the fit of some sex and race combinations. This study presents the development of a custom-fit respiratory protective device (RPD) which conforms to a user's facial features and flexes and moves with facial movements during use. Our design also integrates a pressure-sensing network, which continuously monitors fit and will alert the user when the fit is compromised. In this Part II of the three-part series, we design and incorporate a continuous fit monitoring system in the RPD designed in Part I to enhance its role in protecting users from inhalation hazards in an effective manner during its use. The fit monitoring system comprises a fabric-based sensor network integrated into the RPD and an Android-based App designed to alert the user when the pressure at the faceseal falls below a given threshold established during the initial configuration of the RPD for the user. We also develop algorithms for the incorporation of the sensor slots and data buses into the custom-fit RPD using the Taxonomy of Landmarks defined in Part I. We enhance the structure developed in Part I to secure the sensor network during the use of the RPD. We develop algorithms for customizing a fastening hub to suit the head profiles of individuals to enable them to don the RPD quickly, easily, effectively, and in a repeatable manner. We demonstrate the successful application of the total design methodology by creating digital prototypes for three individuals with different facial profiles and make further advances to our goal of ensuring equitable respiratory protection for all including children, for whom RPDs are currently limited.