Stabilization Device Research Articles

Traction-assisted endoscopic submucosal dissection of colonic lesions: a North American experience

Background and aimsTraction-assisted ESD (TA-ESD) is a proposed technique to improve the efficiency and efficacy of ESD. Multiple studies primarily from Asian centers yielded mixed results in terms of procedure time, en bloc resection rate and R0 resection rate in comparison to conventional ESD (C-ESD). We performed the first comparison of TA-ESD and C-ESD at a high-volume North American center. MethodsThis was a retrospective cohort matched study of all patients who underwent colonic ESD at a single center in the United States by a single operator. The study group were patients who underwent TA-ESD and were matched with a C-ESD case on a 1:1 basis based upon location within the colon, lesion size, and scope stabilization device usage. The baseline characteristics and procedure-related outcomes were compared between the groups. Results138 colonic ESD cases were included (69 TA-ESD, 69 C-ESD). There were no significant differences in the baseline characteristics between the groups. Mean procedure time was 91.0 min (SD 32.5) for TA-ESD and 85.4 min (SD 39.3) for C-ESD (p=0.36). En bloc resection was achieved in 69 (100%) of the TA-ESDs and 67 (97.1%) of the C-ESDs (p=0.15). R0 resection was achieved in 52 (75.4%) of the TA-ESDs and 48 (69.6%) of the C-ESDs (p=0.45). ConclusionWe did not show a significant difference in procedure time, en bloc resection, R0 resection, or adverse events. Further randomized prospective studies that are sufficiently powered and stratified by operator experience level are needed to further elucidate the utility of the technique.

Reliability of a new stabilization device for measurement of muscle strength using a hand-held dynamometer.

The hand-held dynamometer (HHD) is a reliable and portable tool for quantitatively assessing muscle strength. However, a number of variables, including the strength of the tester, the adequacy of stabilization, and the selected testing position, can affect the reliability of the device. The objective of the present study was to examine the reproducibility and inter-rater reliability of strength assessments using HHD with and without a stabilization device. Strength assessments were conducted with and without the stabilization device by two independent raters. Healthy volunteers with no history of musculoskeletal disorders were included in the study. The strength of the shoulder flexion, scapula elevation, knee extension, and hip abduction muscle groups was evaluated using HHD. The reliability of the measurements was evaluated using intra-class correlation (ICC), standard error of measurement, and minimal detectable change. Fifty-two healthy volunteers (age 21.51 ± 2.02 years) participated in the study. The reproducibility was found to be excellent (ICC = 0.89-0.99). While reliability between the assessors was good to excellent (ICC = 0.85-0.93), reliability between assessors and device was found moderate to good (ICC = 0.48-0.78). The strength values obtained for all directions of movement with the stabilization device were found to be significantly higher than those obtained without fixation of the HHD. It can be concluded that the data obtained from the assessors and HHD with stabilization device are not comparable. Moreover, the utilization of a stabilization device may serve to enhance the reliability of the measurements by eliminating the rater effect.

Research on coupling analysis and decoupling control of two-degree-of-freedom PTZ system

Abstract With the development of technology, especially in areas such as robotics, aerospace, photography, and videography, gimbal systems, as an important stabilization device, have been widely used. However, the two-degree-of-freedom gimbal system also faces a series of challenges in practical applications. Among them, one of the most critical issues is the internal coupling phenomenon in the system. The coupling phenomenon refers to the mutual influence and a constraint relationship between different degrees of freedom in the system, which may increase the complexity of the system’s dynamic characteristics and make the design and implementation of control strategies difficult. This study aims at explore more advanced and practical decoupling control strategies through in-depth analysis of the coupling characteristics of the two-degree-of-freedom gimbal system, providing new ideas and methods for the further optimization and application of the gimbal system.

Performance Analysis of an Aerial Remote Sensing Platform Based on Real-Time Satellite Communication and Its Application in Natural Disaster Emergency Response

The frequency of natural disasters has increased recently, posing a huge threat to human society. Rapid, accurate, authentic, and comprehensive acquisition and transmission of disaster information are crucial in emergency response. In this paper, we propose a design scheme for an aerial remote sensing platform based on real-time satellite communication. This platform mainly includes a civilian heavy-duty unmanned aerial vehicle, ground observation system with the self-developed orthographic image stabilization device, wireless communication system with an airborne mobile communication device using Ku band, ground satellite information receiving station, and data processing and application analysis system. The image stabilization capability of the ground observation system and the communication capability of the wireless communication system were verified through ground and flight tests respectively. The results showed that the stability accuracy of the platform was better than the theoretical threshold, the system transmission rate was not less than 2 M bandwidth, the data packet loss rate was low, and the time delay was not more than 2 s. The images captured in the experiment were clear, with a resolution of less than 1cm and an overlap rate of more than 70%. These all results meet the emergency observation requirement, which indicates that the aerial remote sensing platform based on real-time satellite communication has great potential for application in natural disaster emergency response.

Using the principle of gravitational stabilization and orientation in the design of small spacecraft

Currently, most small spacecraft (MCAS) are becoming increasingly relevant in the modern space industry. To successfully complete the tasks assigned to them, the ICS must be oriented in some way in space relative to the Earth. The orientation and stabilization system (SOS) is responsible for this task, which is necessary for monitoring and controlling the position of the MC in space. At the moment, the tasks for the MCA basically do not require complex turning maneuvers and high orientation accuracy, therefore passive and combined SOS have become widespread for them. Such systems have a long service life, are characterized by simplicity, high reliability and low weight. One of the typical systems used in modern space technology is gravity systems. The principle of gravitational SOS is based on the use of gravity acting on a body and moments of inertia relative to three mutually orthogonal axes. This article proposes a 3U CubeSat ICA project with a gravitational orientation system. The design of such a satellite requires a gravitational stabilization device, which is necessary to deploy the ICA after separating it from the launch vehicle, as well as to create a restoring moment. The gravitational device is supposed to be placed between the rigidly bonded 2U MC and the third U MCA. The advantage of this design is the fact that it becomes possible to place more payload on the MC without overloading it with various devices for the orientation and stabilization system.

Effect of Kerosene Dual-Jet Spacing on the Mixing and Combustion Characteristics of a Scramjet Combustor.

As the core of a hypersonic propulsion system, the effective mixing efficiency of fuel and air in a supersonic combustor is crucial for its performance. This study focuses on a cold supersonic flow and employs computational fluid dynamics (CFD) techniques combined with Euler-Lagrange method's discrete-phase model (DPM) for multiphase flows, K-H and R-T (Kelvin-Helmholtz and Rayleigh-Taylor) mixing and atomization models, turbulence models, and surface evaporation models to investigate the injection, atomization, and mixing characteristics of kerosene in supersonic airflow. In order to enhance the mixing efficiency between kerosene and air while reducing flow losses, this study examines a staggered dual-jet injection scheme, with the dual jets arranged at the center of the cavity and having a dual-jet spacing of 10 and 20 mm, respectively. Starting from the interaction mechanism between jets, the impact of different staggered dual-jet spacings on the kerosene jet penetration height, span expansion area, angle of the shock wave, and Sauter mean diameter distribution was analyzed. The results show that a short dual-jet spacing (10 mm) leads to greater penetration height, wider span expansion, and a larger angle of the shock wave. When the dual-jet spacing is shorter, the interaction between the fuel jet and the cavity shear layer is stronger, resulting in an improved fuel mixing efficiency. The achievements of this study are consistent with previous experimental measurements and the literature, demonstrating a strong theoretical foundation for optimizing the design of hypersonic engines by deepening the understanding of the fundamental atomization mechanisms of kerosene jets in cold-state supersonic flows. Moreover, these results hold practical significance in improving the efficiency of kerosene combustion and enhancing the performance of flame stabilization devices.

Comparing immobilisation devices in gynaecological external beam radiotherapy: improving inter-fraction reproducibility of pelvic tilt.

The aim was to determine which immobilisation device improved inter-fraction reproducibly of pelvic tilt and required the least pre-treatment setup and planning interventions. Sixteen patients were retrospectively reviewed, eight immobilised using the BodyFIX system (BodyFIX®, Elekta, Stockholm, Sweden) and eight using the Butterfly Board (BB) (Bionix Radiation Therapy, Toledo, OH, USA). The daily pre-treatment images were reviewed to assess setup variations between each patient and groups for pelvic tilt, pubic symphysis, sacral promontory and the fifth lumbar spine (L5). Compared with the planning CT, pelvic tilt for most patients was within ±2° using the BodyFIX and ± 4° for the BB. The Butterfly Board had a slightly higher variance both for patient-to-patient (standard deviation of the systematic error) and day-to-day error (standard deviation of the random error). Variance in position between individual patients and the two stabilisation devices were minimal in the anterior-posterior (AP) and superior-inferior (SI) direction for the pubic symphysis, sacral promontory and L5 spine. Re-imaged fractions due to pelvic tilt reduced by about half when BodyFIX was used (39.1% BB, 19.4% BodyFIX). One patient treated with the BB required a re-scan for pelvic tilt. Three patients required a re-scan for body contour variations (two using BodyFIX and one with the BB). BodyFIX resulted in a more accurate inter-fraction setup and efficient treatment and is used as the standard stabilisation for gynaecological patients at our centre. It reduced the pelvic tilt variance and reduced the need for re-imaging pre-treatment by half.

LEVEREGING TECHNOLOGICAL HEREDITY TO INCREASE PRODUCTION EFFICIENCY OF FERROCERRAMIC PRODUCTS DURING FINAL MACHINING

The quality state of grinded surface of ferro ceramic products is formed under the influence of thermomechanical phenomena which occurs during final machining and depends on the technological conditions for workpiece procurement. The mathematical model was formulated to regulate and optimize thermomechanical processes during the acquisition of ferroceramic workpieces. This mathematical model describes thermomechanical processes during workpieces sintering. Thermomechanical processes have a direct influence on defects formation in the workpieces. Grinding can cause the appearance of burns, cracks, tensile stresses in the surface layers of the products. These defects can significantly spoil the quality of products during their operation. High thermal stress of diamond-abrasive processing brings thermophysical aspects as a dominating factor for quality characteristics of processed surface. Existing grinding methods for products made from ferrocerramic materials are not able to fully eliminate the defects in the surface layer. Such defects are inherited from preceding machining operations, particularly from workpiece procurement. Material structure itself is prone or defect occurrence due to micro-heterogeneities, packaging defects, dislocations, and structural transformations. Analysis of the thermomechanical processes that run inside the surface layer made it possible to formulate calculation dependencies for defining technological conditions for eliminating burns and cracks during grinding of ferrocerramic products. Device for automatic stabilization of thermomechanical characteristics that accompany grinding of ferrocerramic products. This is achieved through the selection of optimal technological conditions for machining of the products that have heredity inhomogeneities inside the surface layer. Thus, this approach helps to achieve maximum efficiency within required quality citeria.

Combined Control for a Piezoelectric Actuator Using a Feed-Forward Neural Network and Feedback Integral Fast Terminal Sliding Mode Control.

In recent years, there has been significant interest in incorporating micro-actuators into industrial environments; this interest is driven by advancements in fabrication methods. Piezoelectric actuators (PEAs) have emerged as vital components in various applications that require precise control and manipulation of mechanical systems. These actuators play a crucial role in the micro-positioning systems utilized in nanotechnology, microscopy, and semiconductor manufacturing; they enable extremely fine movements and adjustments and contribute to vibration control systems. More specifically, they are frequently used in precision positioning systems for optical components, mirrors, and lenses, and they enhance the accuracy of laser systems, telescopes, and image stabilization devices. Despite their numerous advantages, PEAs exhibit complex dynamics characterized by phenomena such as hysteresis, which can significantly impact accuracy and performance. The characterization of these non-linearities remains a challenge for PEA modeling. Recurrent artificial neural networks (ANNs) may simplify the modeling of the hysteresis dynamics for feed-forward compensation. To address these challenges, robust control strategies such as integral fast terminal sliding mode control (IFTSMC) have been proposed. Unlike traditional fast terminal sliding mode control methods, IFTSMC includes integral action to minimize steady-state errors, improving the tracking accuracy and disturbance rejection capabilities. However, accurate modeling of the non-linear dynamics of PEAs remains a challenge. In this study, we propose an ANN-based IFTSMC controller to address this issue and to enhance the precision and reliability of PEA positioning systems. We implement and validate the proposed controller in a real-time setup and compare its performance with that of a PID controller. The results obtained from real PEA experiments demonstrate the stability of the novel control structure, as corroborated by the theoretical analysis. Furthermore, experimental validation reveals a notable reduction in error compared to the PID controller.

Low-complexity continuous-variable quantum key distribution with true local oscillator using pilot-assisted frequency locking

In the domain of continuous variable quantum key distribution (CV-QKD), a significant challenge arises in achieving precise frequency synchronization, an issue commonly termed as frequency locking. This involves matching the optical frequencies of both the quantum signal laser and the local oscillator laser for accurate symbol demodulation during the exchange of quantum keys. As such, implementations today still grapple with maintaining precise synchronization between sender and receiver frequencies, occasionally hindering the efficiency and reliability of the information exchange. Addressing this challenge, we present and empirically validate a novel approach to CV-QKD by incorporating a pilot tone-assisted frequency locking algorithm to enhance stability when using a locally generated local oscillator (LLO) at the receiver. The proposed design leverages software-based optimization techniques, thereby eliminating the need for high-speed electronic stabilization devices and achieving efficient performance at typical repetition rates. Specifically, the introduction of the pilot tone algorithm allows us to effectively mitigate phase fluctuations and preserve the integrity of the quantum signals during transmission without resorting to time-multiplexed reference pulses or fast-locking electronics in the lasers. Our results suggest the potential for achieving secure key rates of up to 1 Mb/s over a 50 km single-mode fiber when using these techniques, offering promising insights into the feasibility of high-rate, low-complexity CV-QKD implementations under realistic conditions.

Glycerol Triacetate-Based Flame Retardant High-Temperature Electrolyte for the Lithium-Ion Battery.

Rechargeable batteries that can operate at elevated temperatures (>70 °C) with high energy density are long-awaited for industrial applications including mining, grid stabilization, naval, aerospace, and medical devices. However, the safety, cycle life, energy density, and cost of the available high-temperature battery technologies remain an obstacle primarily owing to the limited electrolyte options available. We introduce a flame-retardant electrolyte that can enable stable battery cycling at 100 °C by incorporating triacetin into the electrolyte system. Triacetin has excellent chemical stability with lithium metal, and conventional cathode materials can effectively reduce parasitic reactions and promises a good battery performance at elevated temperatures. Our findings reveal that Li-metal half-cells can be made that have high energy density, high Coulombic efficiency, and good cycle life with triacetin-based electrolytes and three different cathode chemistries. Moreover, the nail penetration test in a commercial-scale pouch battery using this new electrolyte demonstrated suppressed heat generation when the cell was damaged and excellent safety when using the triacetin-based electrolyte.

Time performance of scoop stretcher versus vacuum mattress for prehospital spinal stabilization: open-label simulation-based randomized controlled trial

Recent research has yielded conflicting results on the use of spinal stabilization in prehospital care, with some guidelines expressing concerns about its potential lack of benefit or harm. Transportation on a backboard can cause pain, discomfort, and pressure ulcers, whereas the log-roll technique can cause unnecessary movement and aggravate existing injuries. The scoop stretcher and vacuum mattress provide comparable or better immobilization and comfort than the backboard. Prehospital time is critical, and patients with life-threatening conditions should undergo rapid stabilization procedures. Despite this, some studies have overlooked the scoop stretcher as a spinal stabilization device. The primary goal was to compare the time required to achieve spinal stabilization using a scoop stretcher versus a vacuum mattress. This was a monocentric, parallel, randomized (sealed envelope), superiority, open-label, controlled simulation experiment. All student paramedics, registered paramedics, and EMTs who work in the participating EMS were eligible to participate in the study apart of the study team. The experimental group had to use a scoop stretcher, whereas the control group used a vacuum mattress. Fifteen participants were included. The scoop stretcher group required less time to complete the stabilization procedure (median [Q1; Q3]: 127 seconds [111;145] versus 212 [156;237], p=0.005). Using a scoop stretcher for spinal stabilization is more time-efficient than a vacuum mattress, making it a viable option for unstable trauma patients in the prehospital setting. More research is needed to determine its efficacy in actual clinical practice.

The therapeutic value of vacuum external fixation in polytrauma patients with multiple ribs fracture.

Multiple displaced rib fractures often result in a poor prognosis. Open reduction and internal fixation has been shown to provide benefits for patients with displaced rib fractures and flail chest. Nevertheless, for patients who are unwilling or unsuitable for surgery, the therapeutic options are limited. We developed a novel plastic vacuum device for rib fractures external stabilization. This study aims to compare the therapeutic efficacy of this device against a traditional chest strap in polytrauma patients with multiple rib fractures. A retrospective investigation was conducted on polytrauma patients with multiple rib fractures admitted to our trauma center between March 2020 and March 2023. Patients were categorized into two groups: vacuum external fixation and chest strap. Comparative analysis was conducted on baseline parameters, injury characteristics, and clinical outcomes between the two groups. In this study, 54 patients were included, with 28 receiving chest strap and 26 undergoing vacuum external fixation. Results showed that, at 3days and 7days postintervention, the vacuum external fixation group had significantly lower visual analog scale scores during deep breathing and coughing (P< .05). Vacuum external fixation also reduced pleural drainage duration and volume, as well as lowered the risk of pneumonia and other complications (P< .05). Furthermore, the vacuum external fixation group demonstrated notable improvements in vital capacity, tidal volume, blood-gas test results, and a shorter hospital length of stay. According to the study findings, vacuum external fixation appears to offer benefits to patients with multiple rib fractures, potentially reducing the risk of complications and improving overall clinical outcomes.

A Self-Designed Endobutton Installation Device for Coracoclavicular Stabilization in Acute Rockwood Type III Acromioclavicular Joint Dislocation.

Endobutton technique could provide flexible coracoclavicular (CC) stabilization for acromioclavicular joint (ACJ) dislocation and achieved good clinical outcomes. However, the difficult part of this technique was placement of the Endobutton to the coracoid base. In this study, we designed an Endobutton installation device to place the Endobutton at the coracoid base. And we examined the clinical and radiographic outcomes of patients with acute Rockwood type III ACJ dislocation repaired with Endobutton using this device. We designed an Endobutton installation device to place the Endobutton at the coracoid base to achieve CC stabilization. We retrospectively reviewed 42 patients with acute Rockwood type III ACJ dislocation who underwent CC stabilization with Endobuttons placed either using this novel device (group I, n = 19) or the traditional technique (CC stabilization without using special device, group II, n = 23) from January 2015 to April 2020. The two groups were compared regarding the operative time, intraoperative blood loss, and clinical and radiologic outcomes at final follow-up. The operation-related complications were also evaluated. The Student's t test and the Mann-Whitney U-test were used to compare differences in continuous variables. Differences in categorical variables were assessed with either the Pearson's chi-squared test or Fisher's exact test. Forty-two patients were clinically followed up for a minimum of 12 months. Compared with group II, group I had a significantly shorter mean operative time (56.05 ± 7.82 min vs. 65.87 ± 7.43 min, p < 0.01) and significantly lesser mean intraoperative blood loss (67.89 ± 14.75 mL vs. 94.78 ± 25.01 mL, p < 0.01). At final follow-up, there were no significant differences between the two groups in the visual analog scale score for pain, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand score, and postoperative CC distance of the affected side. Loss of reduction occurred in four patients in group I and three patients in group II (p = 0.68); there were no other operation-related complications in either group. The Endobutton installation device makes placement of the Endobutton at the coracoid base easier and achieves satisfactory clinical and radiologic outcomes without additional complications in acute Rockwood type III ACJ dislocation.

Effects of modified hybrid resistance training on dynamic control ratio of knee joint in untrained healthy subjects

Background: Increased physical inactivity due to the COVID-19 pandemic has the potential to cause leg muscle strength decline due to the decrease in muscle mechanical loading. The hybrid training method uses the force generated by an electrically stimulated antagonist muscle to provide resistance to a voluntarily contracting agonist muscle. This exercise might be an effective choice for strengthening exercises during a pandemic because it does not require external resistance or stabilization devices. In addition, engaging the eccentric contraction of the antagonist muscle while the agonist is contracting concentrically may reduce agonist-antagonist muscle imbalance and reduce the risk of injury. Because the hybrid training system device was difficult to replicate, modifications were carried out using conventional stimulation tools. Methods: The research was conducted at the Medical Rehabilitation Installation of Dr. Soetomo General Academic Hospital Surabaya. The research subjects were 24 untrained healthy men aged 18-40 years divided into two groups: the treatment group who received modified hybrid strengthening exercises and the control group who received Russian protocol neuromuscular electrical stimulation (Russian NMES), 3 times per week for 4 weeks. Statistical tests were carried out on 12 treatment group subjects and 12 control group subjects who were able to complete the study. Results: There was a decrease in non-dominant 60o/sec DCR (p-value 0.002) and non-dominant 120o/sec DCR (p-value 0.019) in the treatment group. There was no significant difference in 60o/sec and 120o/sec DCR on both sides of the leg in the control group. There is a significant difference in ΔDCR between the two groups at non-dominant DCR 120o/sec (p-value 0.036). Conclusion: There was a greater reduction of knee joint DCR in the modified hybrid resistance training compared to the Russian NMES in untrained healthy subjects.

Microstructural and tribological properties of TiO2/Ag multilayer coatings using magnetron sputtering technique for potential applications in non-permanent implants

The development of ideal surfaces for metal implants and osseous stabilization devices requires consideration of various phenomena. These include the formation of bacterial biofilms on the surface, which can lead to infections or rejection of the device. Additionally, the overgrowth of bone material around these devices can create a barrier to their removal once their function has been fulfilled. Due to this, the development of multilayer antibacterial coatings of TiO2/Ag on Ti6Al4V substrates was studied for potential use in non-permanent implants. Magnetron Sputtering technique, which provides significant control over the microstructural features was used to deposit 10 and 15 TiO2/Ag bilayers, resulting in coatings with a uniform and packed structure. Additionally, TiO2 monolayer was used as a comparative sample. Consequently, the properties of the developed systems were characterized using scanning electron microscopy/energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, tribologic assays and surface properties such as rugosity and wettability. Experimental results confirm the presence of crystalline anatase in all systems and an increase both in thickness and roughness as the bilayer number increases compared to TiO2 monolayer coatings. Multilayer coatings evince decreased wettability and crystallinity with higher bilayer counts compared to the highly hydrophobic nature of Ti6Al4V substrates (>90°). Both systems, 10 and 15 multilayer coatings present a thickness of approximately 730 nm and improved hydrophilicity with contact angles of 68.5° and 55.2° respectively, while the TiO2 monolayer grew around 1300 nm and had a contact angle of 86.3° Finally, the tribological properties improve as the silver content on the surface increases as the noble metal tends to accumulate in nanoparticles on the outermost layers of the multilayer systems, exhibiting its solid lubricating effect, however, the wear rate increases for 15TiO2-Ag sample, as more Ag migrates, altering the coating microstructure.

Novo dispositivo intraoral para prevenção de lesões bucais em pacientes intubados

Oral injuries in patients in Intensive Care Units (ICU) are recurrent, especially during endotracheal intubation, as the presence of the tube added to the teeth in the oral cavity can cause injuries to the tongue and other soft tissues. Ideally, tube stabilization devices should be easy to handle by the hospital staff, should always be available for use in ICUs, in addition to being low cost. The aim of this study was to develop a device for endotracheal tube stabilization and injury prevention in patients. 3D technical drawings were prepared, and the final version of the device was prototyped in polylactic acid and positioned in the patient. When compared to mouthguards described in the literature, it was found that the developed device provided stability for the tube, provided separation of the teeth from the adjacent soft tissues, and prevented the intubated patient from biting the tube, thus contributing to the prevention of traumatic injuries. It was concluded that the device has characteristics that allow stabilization of the endotracheal tube and the prevention of oral lesions in ICU patients, and can be used by hospital nursing staff.

Mechanical assessment of proprietary and improvised pelvic binders for use in the prehospital environment

IntroductionPelvic fractures often result from high-energy trauma and are associated with a 10% mortality rate and significant morbidity. Pelvic binders are applied in suspected pelvic injury to stabilise fractured bone,...

Design and Development of a Novel 3-D Printed External Fixation Device for Fracture Stabilization

BackgroundAn external fixator is an orthopaedic device used to stabilize long bone fractures after high energy trauma. These devices are external to the body and fixed to metal pins going into non-injured areas of bone. They serve a mechanical function to maintain length, prevent bending, and resist torque forces about the fracture area. The purpose of this manuscript is to describe a design and prototyping process creating a low-cost entirely 3-D printed external fixator for fracture stabilization of extremity fractures. The secondary objective of this manuscript is to facilitate future advancements, modifications, and innovations in this area of 3-D printing in medicine.MethodsThis manuscript describes the computer aided design process using desktop fused deposition modeling to create a 3-D printed external fixator system designed for fracture stabilization. The device was created using the orthopaedic goals for fracture stabilization with external fixation. However, special modifications and considerations had to be accounted for given the limitations of desktop fused deposition modeling and 3-D printing with plastic polymers.ResultsThe presented device accomplishes the goals of creating a construct that can be attached to 5.0 mm metal pins, allows for modularity in placement orientations, and facilitates adjustable lengths for fracture care. Furthermore, the device provides length stability, prevention of bending, and resists torque forces. The device can be printed on a desktop 3-D printer using standard low-cost polylactic acid filament. The print time is less than two days and can be completed on one print bed platform.ConclusionsThe presented device is a potential alternative for fracture stabilization. The concept of a desktop 3-D printed external fixator design and method of production allows for numerous diverse applications. This includes assisting areas with remote or limited access to advanced medical care and large-scale natural disasters or global conflicts where large volumes of fractures exceed the local medical supply chain capabilities. The presented device creates a foundation for future devices and innovations in this fracture care space. Further research is needed on mechanical testing and clinical outcomes with this design and initiative in fracture care before clinical application.

Clavicular Tunnel Widening After Acromioclavicular Stabilization Shows Implant-Dependent Correlation With Postoperative Loss of Reduction

The aim of this retrospective cohort study was to radiographically describe, quantify and compare clavicular tunnel widening (cTW) of two different types of stabilization devices and investigate a possible correlation between cTW and loss of reduction. In a retrospective analysis of single-center registry data, we compared patients who were treated for an acute AC dislocation (Rockwood types III to V) with either the AC Dog Bone (DB) or low-profile AC (LP) repair systems. On 6-week and 6-month postoperative radiographs, we measured clavicle height and tunnel diameter. We calculated the button/clavicle filling (B/C) ratio to quantify how much of the clavicular tunnel height is covered by the low-profile inlet. The association between B/C ratio and the extent of cTW was defined, and we also compared cTW between treatment groups. Reduction of the AC joint was graded as either stable, partially dislocated or dislocated depending on the AC ratio. A two-sample t-test was used for comparing cTW progression between the two groups. For continuous variables between more than two groups, the Kruskal-Wallis test was used. Of 65 eligible patients, there were 37 and 28 included in the DB and LP groups, respectively. Overall, cTW was conically shaped with transclavicular widening noted in the DB group and cTW developing strictly inferior to the button in the LP group. For both implants, mean maximal cTW was 7.1mm and located at the inferior cortex; the B/C ratio was not associated with increased inferior cTW (r=-0.23, P=0.248). Only LP patients with complete loss of reduction had significantly increased cTW (P=0.049). Conical-shaped cTW is a common implant-independent phenomenon after AC stabilization using suture-button devices. It occurs only at the suture-bone interface and is less excessive for the LP implant. There is an association between increased cTW and loss of reduction specific to the LP implant only.