Socket Type Research Articles

In vivo experimental study comparing alveolar ridge preservation versus guided bone regeneration after unassisted socket healing at intact and damaged sites in narrow alveolar ridges.

To compare bone regeneration and dimensional alteration of alveolar ridge at intact and damaged extraction sockets after alveolar ridge preservation (ARP) and implant placement versus unassisted socket healing followed by guided bone regeneration (GBR) with simultaneous implant placement. In 6 beagle dogs, 3 types of extraction sockets in the mandible were created: (1) intact sockets, (2) 1-wall defect sockets and (3) 2-wall defect sockets. The sockets were allocated to undergo either (1) ARP and implant placement 8weeks later (ARP group) or (2) GBR with simultaneous implant placement after 8weeks of unassisted socket healing (GBR group). After an additional healing period of 8weeks, bone regeneration and dimensional changes were evaluated radiographically and histologically. GBR showed superior bone formation and greater bone gains compared to ARP, regardless of the initial extraction-socket configuration. Although ARP maintained the preexisting alveolar ridge dimensions, peri-implant bone defects were still detected at 8weeks of follow-up. Histomorphometric analyses confirmed that GBR increased dimensions of the alveolar ridge compared to baseline, and the augmentation and bone regeneration were greater with GBR than with ARP. Early implant placement with ARP can mitigate alveolar ridge changes in the narrow alveolar ridge. However, early implant placement with simultaneous GBR creates the conditions for enhanced bone regeneration around the implant and greater ridge augmentation compared to ARP, irrespective of the extraction-socket configuration.

New Technique of Glenohumeral Joint Dissection

Objectives: Glenohumeral is a ball and socket type of synovial joint which permits a wide range of movement. During the typical shoulder joint dissection, we are unable to see the intracapsular view of shoulder joint. Methods: A dissection technique that was performed in Sharir Rachana Dept. of NIA, Jaipur, which exposes the glenohumeral joint's internal capsule, the glenoid labrum, the proximal insertion of the long head of the biceps tendon, and the surfaces of the joint while protecting the posterior aspect of the capsule and the surrounding muscles and tendons that support the joint. Results: This new dissection method allowed the preservation of glenohumeral joint structures and provides a better understanding of its intracapsular view and related structures. Conclusion: The glenohumeral joint can be dissected using this new technique, by which we can prevent the damage to the structures that surround it and enabling visualization of its intracapsular view.

Accuracy of open-sleeved vs. closed-sleeved static computer-assisted implant systems in immediate maxillary molar implant placement: An invitro study.

The objective of this study is (1) to compare the accuracy of an open-sleeved static computer-assisted implant system (sCAIS) with a closed-sleeve sCAIS and free-hand approach in immediate implant placement (IIP) of maxillary molar sites and (2) to investigate the influence of socket morphology on these approaches. Ninety partially edentulous duplicated maxillary models simulating three different molar sockets (type A, B, and C based on Smith and Tarnow's classification) were investigated. Three modalities, including sCAIS with open-sleeves, sCAIS with closed-sleeves, and free-hand approach, were applied separately to 30 models with 120 sockets. A customized Python script automatically measured the deviations between the virtual and actual implant positions for all 360 implants. The 3D deviations of sCAIS were significantly influenced by the socket and sleeve types. Both guided groups exhibited significantly less deviation than the free-hand approach. Type A and C sockets resulted in better implant positions than type B socket sites. In type B sockets, the open-sleeve group achieved significantly less deviation compared to the closed-sleeve group, with respect to apical global (1.34 ± 0.53 vs. 1.84 ± 0.59 mm), coronal horizontal (0.68 ± 0.36 vs. 0.93 ± 0.34 mm), apical horizontal (1.21 ± 0.59 vs. 1.74 ± 0.63 mm), and angular (3.30 ± 1.41 vs. 4.41 ± 1.96°) deviations. Guided implant surgery significantly reduces deviations during molar IIP compared to free-hand procedures. Furthermore, the use of open-sleeve sCAIS appears to be more effective in minimizing deviations in type B sockets when compared with the closed-sleeve guided system.

Evaluation of Novel Prosthesis Implant Adapter by Finite Element Analysis

Osseointegration prosthesis is a directly implanted fixation in the bone for limb amputees. It has been used as an excellent alternative for amputees experiencing difficulties from the use of a traditional socket type prosthesis. A novel implant used for implanted prosthetics is designed and it depended on polymer as a primary material to increase bone osseointegration. As an alternative to the metallic material on the interface with the bone. The design consists of several parts and relies on thread to increase installation. This research aims to overcome the problems of loss implantation by using new designs for fixations. Evaluated this design by FEA (Finite element analysis) in different load cases to obtain the distribution of stress and force reaction when the implant displacement was applied. The polymeric part was designed in two shapes, each shape relies on a different size of threaded to verify the change of fixation with the threaded. As for the metal part, two cases were used, the first case, stainless steel 316L, and the second case titanium metal to reach the best stress distribution in this design.

TEMPLATE DESIGN FOR TRANSFEMORAL PROSTHETIC SOCKET DEVELOPMENT

The presented paper aims to design 3D templates of the sciatic muscle and thigh to simplify and speed up the process of modelling TF (transfemoral) sockets using the CAD/CAM method. A proposal for a general procedure for modelling the proximal part of the TF socket and a thorough description of the proximal part and the types of sockets that are used is presented. Ten individual scans of positives of TF amputated limbs were obtained from which ten mounting ring templates were designed via CAD modelling in the Autodesk Meshmixer software. In the last step a production simulation was generated in PrusaSlicer software for the overall price evaluation.

Bending Performance of the Steel Longitudinal Joint for Quasi-Rectangular Pipe-Jacking Tunnels

Pipe jacking is a special tunneling method for installing underground pipelines or tunnels with the minimum surface disruption. Longitudinal pipe-to-pipe joints are important for tunnels with the pipe-jacking technique. The longitudinal joint generally adopts the socket type, that is, a bell-and-spigot joint, designed for use with gaskets work well for jacking. The joints should have sufficient bearing surfaces to transmit the required axial thrust and have the ability to resist lateral forces from ground movements during tunnel construction and operation. This paper focuses on the mechanical performance of the longitudinal joint of the superlarge cross section quasi-rectangular pipe-jacking tunnel under the action of local bending moments caused by lateral forces. A full-scale ultimate bending test of the local joint specimen was carried out to study its bearing mechanism, ultimate bearing capacity, and failure mode. Numerical simulations were then employed to analyze the performance of the joint specimen and were verified by the experimental results. The damage evolution process and bearing mechanism changes of the joint specimen were analyzed by numerical simulations. The results show that the bell part contributes much more to the bending of the joint than the spigot part. The bolt contributes little to the bearing capacity and stiffness of the joint but plays a role in positioning the pipe to pipe in the installation. The bending failure of the joint is characterized by weld fractures between the longitudinal rib and its flange next to the V-groove weld at the bottom of the bell part. The V-groove weld connecting the bottom of the spigot part and the bell part primarily affects the bending capacity of the joint.

The anatomic classification of the anophthalmic eye socket (Types 0–V): A high-level taxonomy classification system

Eyelid and orbital deformities caused by various defects, such as tumor resection and trauma, whether congenital or acquired, are extremely complex and atypical. Several classifications systems for these anophthalmic conditions have been developed, but none have proven suitable for determining the ideal reconstructive surgical strategy. We therefore designed a novel system known as the Anatomic Classification of the Anophthalmic Eye Socket (Types 0-V) for optimum reconstruction of anophthalmic socket deformities focusing on eyelid and orbital defects. Type 0 is an eyelid defect type, in which only the eyelid is defective; Type I is a phthisis bulbi type, in which the anatomical eyeball is preserved, but the visual function is lost; Type II is a substitution type involving filling with implant packing after evisceration or enucleation; Type III is an enucleation type involving enucleation of the ophthalmus; Type IV is an exenteration (incomplete) type involving exenteration while saving the eyelids; and Type V is an exenteration (complete) type involving exenteration including eyelid defects. Using this classification system, it will be possible to standardize reconstructive procedures of the anophthalmic socket.

Morphological Characteristics of Maxillary Molars Interradicular Septum and Clinical Implications -What Do We Know So Far?

Abstract The interradicular septum describes area in the root furcation that separate alveoli of multi-rooted teeth. The shape and dimension depend of the topography of the extraction socket, the geometry of residual root and anatomy of molars alveoli. The clinical implications of this anatomic structure may be used in oral surgery resection procedures, periodontology and implantology. There is an opinion from the surgical and prosthodontic side that center of interradicular septum may be adequate place for immediate implantation. The aim of this study was to investigate morphological characteristics and clinical implications of upper molars interradicular septum. The studies showed that interradicular septum is important for success of resection surgery procedures: hemi-section, bisection and root amputation. It’s reported that furcation involvement in periodontal disease is clinical sign for severe bone loss. By reviewing the available literature for immediate implantation, it’s reported the clinical implications for diagnostical plan (pre-intervention), presurgical (pre-instrumentation) and intraoperative evaluation of interradicular septum for immediate implantation. The cone beam computed tomography analyze study presented mean values of septum height and wide for hypothetical plan of immediate implant placement. The presurgical studies evaluate how to assure preservation of septum and safe implant position in center of septum. The research showed varies therapy modalities that can be used, and how to choose right therapy according the socket type and initial septum width classification. According to observation of studies results, other researches should be considered for CBCT anatomical structure analyze and measures of interradicular septum for immediate implantation planning.

The Impact of Limited Prosthetic Socket Documentation: A Researcher Perspective.

The majority of limb prostheses are socket mounted. For these devices, the socket is essential for adequate prosthetic suspension, comfort, and control. The socket is unique among prosthetic components as it is not usually mass-produced and must instead be custom-made for individual residual limbs by a prosthetist. The knowledge of what constitutes “good” socket fit is gained by expert prosthetists and technicians over years of experience, and rarely documented. The reliance on tacit knowledge makes it difficult to standardize the criteria for a well-fitting socket, leading to difficulties understanding the impact of socket fit. Despite its importance, the workflow for socket fitting is often overlooked in literature. Due to the customized nature of sockets, if information is provided in literature, generally only the type of socket and suspension mechanism is noted, with information regarding the fitting and manufacturing processes omitted. In this article, the concerns, issues and consequences arising from lack of upper and lower limb socket documentation are discussed from a researcher perspective, supported by healthcare professionals and socket fabrication specialists. Key changes are proposed to the way socket manufacturing and evaluation are documented to assist future research.

Classification Based on Extraction Socket Buccal Bone Morphology and Related Treatment Decision Tree.

Background: Alveolar ridge preservation (ARP) can successfully reduce volumetric ridge changes. However, there is still no consensus on what technique is the most advantageous for each specific clinical scenario. Hence, the aim of the present paper was to provide a treatment decision tree to guide the choice of predictable ARP procedures based on extraction socket buccal bone morphology and integrity. Material and Methods: Three socket types (ST) are proposed and discussed based on buccal bone morphology (intact, dehiscence or fenestration). Results: A decision tree for ARP was developed in order to merge ST classification with suitable treatment modalities. In the decision tree, the issue of when to allow unassisted healing or ARP was discussed. Described methods included bone grafting and collagen plug, and absorbable membrane or non-resorbable membrane, with or without flap elevation. Conclusion: A decision tree for ARP procedures was provided to guide clinicians towards the most conservative and predictable treatment approach based on remaining socket anatomical structures after extraction.

Scanning electron microscopy of cuticular sensory structures on the legs of Micronecta haliploides (Horvath, 1904) and Hydrometra greeni (Kirkaldy, 1898) (Hemiptera: Heteroptera)

Structures on the legs of two hemipteran bugs, Micronecta haliploides (Horvath, 1904) and Hydrometra greeni (Kirkaldy, 1898), belonging to family Micronectidae and Hydrometridae of two infra orders Nepomorpha and Gerromorpha, respectively were investigated using scanning electron microscopy. Both species have a distinctive leg structure bearing specialised cuticular sensory structures. In the study, the sensilla were classified into five basic types: sensilla trichoidea, sensilla basiconidea, sensilla placoidea, porous circular sensilla and sensilla bell mouthed. These sensilla were further differentiated on the basis of shape, size, number, flexibility and type of socket attached. A total of 26 types of sensilla in the legs of these two species were observed. M. haliploides showed 18 types of sensory structures and H. greeni 8 types. A specific morphological structure of the porous circular sensilla was observed and found to be unique.

Examination of T-MCFC Stack with a Socket Type

Recently, global warming and the depletion of fossil fuels are the problems in the world. As the solution to these problems, although fuel cells that makes hydrogen a fuel are highlighted because it does not exhaust CO2 during power generation, CO2 is exhausted in the hydrogen producing process. Therefore, we have been developing High Functional Direct Carbon Fuel Cell (HF-DCFC) composed of Molten Salts Gasification and Tubular Molten Carbonate Fuel Cell(T-MCFC), can use an organic waste as fuel directly. Molten Salts Gasification is able to produce H2 and CO for power generation of T-MCFC by functioning as a thermal catalyst. The previous study has established the manufacturing method of a T-MCFC single cell supported by a stainless tube of φ9. Aiming at commercialization of HF-DCFC, T-MCFC should be stacked to obtain a high power, and the support tube has to be changed from stainless to alumina to avoid short circuit. Therefore, we proposed that the socket type T-MCFC was composed of applying the cathode electrode to inside of the short alumina tube of φ8 and applying the anode electrode to outside of φ20, and the electrolyte thickness was thick 6mm because the alumina tube was used as an electrolyte. The T-MCFC stack was composed of connecting these socket type T-MCFC. However, because the crack was caused in both electrodes of this socket type, this socket type was able hardly to generate electricity by gas cross leakage through these cracks. We consider that these problems originated in the mismatching of a support tube diameter and each cell component thickness, and a presence of fine pores of the support tube. Therefore, these failure factors were confirmed by manufacturing the T-MCFC stack with a stainless support tube with the same diameter as the alumina support tube diameter. As a result, it was clarified that the relation between each cell component thickness and a support tube diameter in the stainless tube was not adaptable to the alumina tube, and the alumina tube was unsuitable to use as the matrix from the viewpoint of the high-resistivity and poor gas seal. Therefore, we confirmed the optimum thickness of each cell component using T-MCFC single cell supported by a stainless steel of φ19. Moreover, the T-MCFC stack was manufactured by connecting two single cells by alumina joint, and the fundamental performance was evaluated. As a result, when each cell component thickness of T-MCFC (φ19) was increased to about 1.5 times that of φ9, the crack of the electrode was hardly caused in the manufacturing process. Figure 1 shows the I-V performance of each T-MCFC. However, the I-V performance of T-MCFC single cell (φ19) was worse than that of others. Because the open circuit voltage of φ19 was lower than the theoretical OCV and the cell resistance was also larger, we judged that the crossover was surely caused. We consider that the oxidation expansion power of the cathode electrode exceeded the shrinkage force of the anode electrode by having increased the thickness of both electrodes by 1.5 times, and consequently the anode electrode and the matrix cracked by the expansion power of the cathode electrode. Therefore, we have to optimize the relation between thickness of each cell component and the diameter of the support tube further. Figure 1

Examination of T-MCFC Stack with a Socket Type

We have been developing High Functional Direct Carbonate Fuel cell (HF-DCFC) composed of Molten Salts Gasification and Tubular Molten Carbonate Fuel Cell (T-MCFC), can use an organic waste as fuel directly. The previous study has established the manufacturing method of a T-MCFC single cell supported by a stainless tube of φ9. Aiming at commercialization of HF-DCFC, T-MCFC should be stacked to output a high power. We proposed that the socket type T-MCFC stack was composed of connecting several single cells supported by alumina tube to avoid short circuit. However, because the crack was caused in both electrodes of this socket type, it was able hardly to generate electricity due to gas cross leakage through these cracks. These failure factors were confirmed by manufacturing the stack with a stainless support tube of φ19. We have developed a new stack composed of connecting two single cells supported by stainless tube and alumina-joint.

Adjustable-Volume Prosthetic Sockets: Market Overview and Value Propositions.

The prosthetic socket is commonly considered to be the most important part of the prosthesis and lack of fit can lead to skin breakdown, reduction in wear, reduction in activity, and consequential deleterious health effects. Furthermore, approximately 90% of amputations are due to a vascular etiology, which affect fluid retention regularity, and even small limb volume fluctuations can lead to lack of fit. Adjustability in the socket volume has been suggested as a potential solution to common fit issues but has lacked market penetration mostly due to lack of reimbursement. Despite this there are several adjustable-volume sockets emerging on the market today including prefabricated, modular, custom with adjustable-volume component, custom with adjustable-volume feature, and adjustable-hybrid sockets. Prefabricated sockets are mass produced in common sizes and fit directly to the patient by a prosthetist using pad kits, BOA dials, or straps. Modular sockets are assembled to a patient or model with panels or struts attached to an adjustable base. Custom sockets with adjustable-volume elements are traditionally-fabricated sockets made to a model of a patient's limb with a volume-adjustable component added or volume-adjustable feature built in. Custom-hybrid sockets are made custom to a model of the patient's limb and incorporate several aspects of the previous socket types and include some radically-unique design aspects which cannot be limited to one category. These adjustable-volume sockets offer several advantages to traditional rigid-volume sockets for the patient, prosthetist, and providing clinic. The micro-adjustability for the patient allows them to alter fit without removing the socket, maintaining a more intimate fit throughout the day than traditional sockets. The macro-adjustability for the prosthetist allows for increased options for fit customization including the ability to reverse or undo changes without necessarily re-making the socket. This allows for the most optimal fit for the patient. Adjustable volume also present efficiencies in the fitting process by simplifying or eliminating steps including residual limb shape capture, form modification, diagnostic fabrication, iterative alteration, and definitive fabrication with the different socket types affecting different steps. Due to these factors, adjustable-volume sockets have disrupted the market to the point where reimbursement reform is needed including additional L-codes in the United States and fee-for-service or fee-for-outcome associated with prosthetic follow-up care. Prosthetic care should also be separated from durable medical equipment to allow for alternative reimbursement models. As reimbursement adapts prosthetists must adapt correspondingly to differentiate their skillset from other allied health providers including incorporating more objective methods to show superior care outcomes. This adaptation should include a continued push for state and municipal licensure of prosthetists.

Hip disarticulation and hemipelvectomy prostheses: A review of the literature.

Although the global population of people with a hip disarticulation (HD) or hemipelvectomy (HP) amputation is small, the degree of disability is high, affecting function and independence. A comprehensive literature review is needed to examine the evidence for prostheses in these amputation levels. A scoping literature review was conducted to examine related research documents from 1950 to September 2020, found using Scopus, Web of Science, PubMed, and Google Scholar databases. Studies evaluated (retrospectively or prospectively) HD or HP prostheses and were written in English. Study design and protocol, research instrument, sample size, and outcome measures were reviewed. In the past 70 years, 53 articles that evaluated HD or HP prostheses were published. Most research was conducted in the United States (24 articles) and Japan (nine articles). In 42 articles, authors prospectively evaluated the effects of prostheses in these amputation levels. On average, prospective studies had four (SD = 5) participants. Since 1950, only five prospective studies evaluated HD or HP prostheses with 10 or more participants. Moreover, sufficient information was often unavailable for research replication. More evidence is needed regarding the effects of HD or HP prosthetic components (i.e. hip, knee, ankle, socket type, and suspension system) on gait, patient satisfaction, prosthetic use, interface pressure, and energy expenditure. Articles mostly have small sample sizes that reduce confidence in the reliability of their findings and limit generalizability. Future investigations are needed with vigorous methodology and larger sample sizes to provide strong statistical conclusions.

Effects of Prosthetic Socket Design on Residual Femur Motion Using Dynamic Stereo X-Ray - A Preliminary Analysis.

Individuals with transfemoral amputation experience relative motion between their residual limb and prosthetic socket, which can cause inefficient dynamic load transmission and secondary comorbidities that limit mobility. Accurately measuring the relative position and orientation of the residual limb relative to the prosthetic socket during dynamic activities can provide great insight into the complex mechanics of the socket/limb interface. Five participants with transfemoral amputation were recruited for this study. All participants had a well-fitting, ischial containment socket and were also fit with a compression/release stabilization socket. Participants underwent an 8-wk, randomized crossover trial to compare differences between socket types. Dynamic stereo x-ray was used to quantify three-dimensional residual bone kinematics relative to the prosthetic socket during treadmill walking at self-selected speed. Comfort, satisfaction, and utility were also assessed. There were no significant differences in relative femur kinematics between socket types in the three rotational degrees of freedom, as well as anterior-posterior and medial-lateral translation (p > 0.05). The ischial containment socket demonstrated significantly less proximal-distal translation (pistoning) of the femur compared to the compression/release stabilization socket during the gait cycle (p < 0.05), suggesting that the compression/release stabilization socket provided less control of the residual femur during distal translation. No significant differences in comfort and utility were found between socket types (p > 0.05). The quantitative, dynamic analytical tools used in the study were sensitive to distinguish differences in three-dimensional residual femur motion between two socket types, which can serve as a platform for future comparative effectiveness studies of socket technology.

164. Biomechanical analysis of the endplate fixation methods of cervical total disc replacement (TDR) prostheses to shear force expulsion

<h3>BACKGROUND CONTEXT</h3> Current methods for achieving immediate endplate fixation with cervical TDR include the use of keels or spiked teeth. Nonphysiologic push-out or expulsion tests are typically used to measure the distraction force and mechanical work required to expulse the device. <h3>PURPOSE</h3> To determine the failure work and load required to expulse the upper and lower components of the 4 different cervical prostheses after undergoing multidirectional cyclic testing. Endplate configurations included single central keel, tripod keel, and spiked teeth. <h3>STUDY DESIGN/SETTING</h3> Each device was implanted in a cervical functional spinal unit (FSU) and cyclically loaded 2,000 times under physiological ranges of combined flexion/extension coupled with axial rotation at a rate of 2.5deg/s. Following cyclic testing, the specimens were disarticulated through the disc space, separated into upper and lower segments and mounted in a robotic testing platform for expulsion testing. <h3>PATIENT SAMPLE</h3> Sixteen (C4-C5) and 16 (C6-C7) FSUs were dissected from 8 male and 8 female cadaveric cervical spines with an average age of 55.9 +/- 9.7 years. Three FSUs were not usable due to poor tissue quality which reduced the sample size to 29 FSUs. <h3>OUTCOME MEASURES</h3> Shear expulsion force and distraction displacement were measured and combined to calculate the expulsion work, the resistive stiffness. The peak expulsion force was also obtained. Normality of the expulsion data was tested using the Shapiro-Wilk test (for p=0.05). If normality failed, a nonparametric Kruskal-Wallis test with Bonferroni correction was used to analyze the data between implant types. An additional test was done to compare the shear expulsion parameters between the upper and lower components of the same implant type. A similar normality test as above was used and a (2 tailed) Mann-Whitney U test was used here when normality failed. <h3>Methods</h3> Four ball and socket type cervical disc prostheses having different endplate fixation features were tested: 1. A clinically used and FDA approved single central keel (SCK), 2. A clinically used (outside the U.S.) low profile teeth (LPT) with domed endplate shape to allow a better fit in case of concave vertebral endplate, 3. A clinically used (outside the U.S.) tripod keel (TK), and 4. Small single keel (SSK). A minimum sample size of 6 implants per prosthesis type were used. Three additional TK disc prostheses and two additional LPT disc prostheses were implanted. A minimum of 6 implants per prosthesis type were used. Specimens were mounted in a robotic testing platform programmed to apply a 50N compressive load to the top surface of the disc, followed by an anterior shear force to the backside of the implant until the device was fully expulsed. <h3>Results</h3> Mean and standard deviations for peak expulsion forces were 69(41)N, 62(21)N, 110(71)N and 78(36)N, expulsion work were 321(225)Nmm, 399(161)Nmm, 463(305)Nmm, and 296(149)Nmm, and resistive stiffness were 81(61)N/mm, 44(42)Nmm, 163(207)Nmm, and 150(149)Nmm. No significant differences occurred between implant types for any of expulsion data. Further, no significant differences were found between the upper and lower components of any implant type except for the expulsion work term of the traditional central keel device (p=0.037). <h3>Conclusions</h3> The distraction failure strength of three different cervical disc prostheses was comparable to an existing FDA approved central-based keel designed disc prosthesis. <h3>FDA DEVICE/DRUG STATUS</h3> Prodisc C (Approved for this indication), Prodisc C Vivo (Investigational/Not approved), Prodisc C Nova (Investigational/Not approved), Prodisc C SK (Investigational/Not approved)

P5. Fixation stability of four different cervical disc prostheses endplate configurations

<h3>BACKGROUND CONTEXT</h3> Motion preservation devices have become increasingly popular in the treatment of spinal pathologies that require biomechanical support following removal of the degenerated tissue. As these devices continue to be developed to treat multiple adjacent diseased spinal levels, like the use of multiple disc prostheses or placement of a disc prosthesis adjacent to a fused level, in-depth biomechanical data that supports these established surgical methods are needed. <h3>PURPOSE</h3> To assess immediate stability of four cervical disc prostheses under low endurance multidirectional cyclic loading conditions in a cadaveric cervical spine model. <h3>STUDY DESIGN/SETTING</h3> Each prosthesis was implanted in a cervical functional spinal unit (FSU) and cyclically loaded 2000 times under physiological ranges of combined flexion/extension coupled with axial rotation at a rate of 2.5deg/s. <h3>PATIENT SAMPLE</h3> There were 16 (C4-C5) and 16 (C6-C7) FSUs dissected from eight male and eight female cadaveric cervical spines with an average age of 55.9 +/- 9.7 years. Three FSUs were not usable due to poor tissue quality which reduced the sample size to 29 FSUs. <h3>OUTCOME MEASURES</h3> A one-way repeated measures ANOVA with a Student Newman-Keuls test was used to compare differences in the combined motion data. Anteroposterior endplate migration of both the upper and lower implant components was measured after 20, 250, 500, 1,000, 1,500 and 2,000 cycles. Tests were stopped if implant component migration exceeded 3mm or endplate fracture was observed, and migrations less than 0.3mm were defined as clinically stable. <h3>METHODS</h3> Four cervical disc prostheses that had a similar ball and socket type articulation mechanism but varying endplate fixation features were tested: 1. A clinically used and FDA-approved single central keel (SCK). 2. A clinically used (outside the U.S.) low profile teeth (LPT) with domed endplate shape to allow a better fit in case of concave vertebral endplate. 3. A clinically used (outside the U.S.) tripod keel (TK) and 4. Small single keel (SSK). A minimum sample size of six implants per prosthesis type were used. Three additional TK disc prostheses and two additional LPT disc prostheses were implanted. Specimens were cyclically tested 2,000 times at a rate of 2.5deg/s to an end limit of 1.5Nm in flexion or extension coupled with 1.5Nm of right and left axial rotation resulting in a total applied moment of 2.25Nm. A one-way repeated measures ANOVA with a Student Newman-Keuls test was used to compare differences in the combined motion data. Anteroposterior endplate migration of both the upper and lower implant components was measured after 20, 250, 500, 1,000, 1,500, and 2,000 cycles. Tests were stopped if implant component migration exceeded 3mm or endplate fracture was observed, and migrations less than 0.3mm were defined as clinically stable. <h3>RESULTS</h3> No statistical difference was found between the combined (flexion plus extension) sagittal plane range of motion or the combined (left plus right) axial motion. All but one of the specimen migration values were below 0.3mm. Upper prosthesis component migration ranged between 0.02mm and 0.08mm and between 0.01mm and 0.04mm for the lower components. No significant differences occurred between the upper components or the lower prosthesis components of any implant type. <h3>CONCLUSIONS</h3> Three different low profile endplate fixation designs for a cervical disc were found to provide comparable immediate holding strength to an existing FDA-approved central-based keel design. <h3>FDA DEVICE/DRUG STATUS</h3> Prodisc C (Approved for this indication), Prodisc C Vivo (Investigational/Not approved), Prodisc C Nova (Investigational/Not approved), Prodisc C SK (Investigational/Not approved).

Fatigue resistance of steel ropes: failure criterion: Background to the verification in prEN 1993‐1‐11:2020

AbstractMany steel rope systems are subjected to fluctuating tensile loads and therefore can fail due to fatigue. Available fatigue test data indicate that rope diameter, mean stress, socket type, lay angle and rope length influence the fatigue resistance. Most of the tests were terminated before full failure of the ropes. This paper shows that the test termination criterion, such as fracture of the first wire, fracture of 5 % of the wires or full rope fracture, has a large influence on the resulting fatigue resistance. A probabilistic analysis is carried out for a rope system in a bridge, demonstrating that the required structural reliability levels are met when considering full failure as the end‐of‐life criterion for ropes.

Construction Features of Devices for Charging Electric Vehicles

The electric vehicle (EV) market is actively developing by leading car manufacturers around the world. The main efforts of developers are aimed at creating an efficient energy storage device - a rechargeable battery, because its parameters largely characterize the EV: power reserve and acceleration, engine power and others. But for the comfortable existence of EV in urban conditions requires a certain infrastructure, which includes charging stations, containing all the necessary equipment to charge the battery. In the results use many different terms and definitions that often describe the same phenomenon. This paper substantiates the need for systematization and analysis of equipment for charging electric vehicles. The methods of charging electric cars are considered in the work, the information on the ways of charging EV is arranged, parallels between different standards are made. Chargers for electric vehicles can be classified as follows: AC charging and DC charging. Both methods of EV charging are regulated by different standards in different countries. The US and Japan use the SAE J1772 standard, it covers both types of charging methods mentioned above. Its European adaptation is IEC 61851. The standard describes the power level of charging stations and types of EV sockets. The charging mode describes the safety communication protocol between the electric vehicle and the charging station. To establish a serial connection between the electric vehicle and the EVSE, there is a function "PILOT", which refers to the protocol IEC 61851, provides the necessary functions related to the communication of EV and EVSE. The connection detection sequence is performed automatically when the EVSE power control cable is physically connected to the EV. Of the many variants of controlled AC chargers, according to the authors, the most promising is the option based on an open project. The advantages are open data on the applied circuit solutions and code, as well as low cost compared to industrial designs, the availability of a user-friendly interface, the ability to create your own mobile application and connect a payment system. The disadvantage of the IEC 61851 protocol is the limited exchange of EVSE data with EV. Because only data on initialization, process and charge stop is transmitted via the exchange channel. The charging station cannot estimate the type of electric car, its characteristics, capacity and battery condition, maximum charging speed, etc. Implementing the above could be useful for creating things like load balancing and the potential for a possible return of electricity to the grid.