Articulated System Research Articles

Experimental study on mechanical behavior and countermeasures of mountain tunnels under strike-slip fault movement

In the seismic mountainous regions such as western China, it is usuallly inevitable to construct tunnels near active fault zones. Those fault-crossing tunnel structures can be extremely vulnerable during earthquakes. Extensive experimental studies have been conducted on the response of continuous mountain tunnels under reverse and normal fault movements, limited experimental investigations are available in the literatures on mountain tunnels with special structural measures crossing strike-slip faults. In this study, a new experimental facility for simulating the movement of strike-slip fault was developed, accounting for the spatial deformation characteristics of large active fault zones. Two groups of sandbox experiment were performed on the scaled tunnel models to investigate the evolution of ground deformation and surface rupture subjected to strike-slip fault motion and its impact on a water conveyance tunnel. The nonlinear response and damage mechanism of continuous tunnels and tunnels incorporated with specially designed articulated system were examined. The test results show that most of slip between stationary block and moving block occurred within the fault core, and significant surface ruptures are observed along the fault strike direction at the fault damage zone. The continuous tunnel undergoes significant shrinkage deformation and diagonal-shear failure near the slip surface and resulted in localized collapse of tunnel lining. The segments of articulated system tunnel suffer a significant horizontal deflection of about 5°, which results in opening and misalignment at the flexible joint. The width of the damaged zone of the articulated system tunnel is about 0.44 to 0.57 times that of the continuous tunnel. Compared to continuous tunnels, the articulated design significantly reduces the axial strain response of the tunnel lining, but increases the circumferential tensile strain at the tunnel crown and invert. It is concluded that articulated design provides an effective measure to reduce the extent of damage in mountain tunnel.

Implementasi Pendekatan Komunikatif (Communication Approach) Dalam Meningkatkan Keterampilan Berbahasa Arab

<p><strong><em>Abstract</em></strong></p><p><em>The approach can be interpreted in English is (approach), which is a statement of establishment, philosophy and belief. Communicative means being able to convey messages well. The communicative approach is a language learning approach that emphasizes the mastery of language skills than language structure Language is a means of communication with each other, so that if someone does communication interaction, of course, must understand each other the object being discussed so that the goals to be achieved will be more directed towards their goals. However, if the interaction is not communicative because it does not understand what is being discussed because it does not understand the language used, causing the expected goals will not be achieved. Language is considered as a skill, not science, so language skills should be able to include four things, namely listening, speaking, reading, and writing. And one of the characteristics of these skills is to be done by continuous training. If one of the methods used previously is a direct method (direct method), then this method is updated so that it becomes an audiolingual method</em><em>.</em><em> The writing of this article aims to describe the application of a communicative approach through various learning methods in Arabic learning to increase language disappearances. The method used is the library research method originating from various library sources. The results of this writing indicate that methods that emphasize more to listening and speaking skills.</em><em> Speaking skills are one type of language ability to be achieved in teaching Arabic. And in essence is a meter of reproducing the flow of the sound system of articulation to convey the will, the needs of feelings, and desires to others. Exercise in Arabic language so that students are able to communicate well and correctly with others. Starting the practice of speaking is based on the ability to listen, the ability to mastery vocabulary and courage to reveal what is in his mind.</em></p>

Comparison of Sagittal Condylar Guidance Angle Obtained by Radiographic Methods and Manual Programming of Articulators in Dentate Patients – A Clinico-radiographic Study

Background: The ultimate goal of advanced procedures in prosthetic dentistry is to construct a prosthesis based on the accurate reproduction of condylar guidance. Aim: To compare the sagittal condylar inclination obtained using the cone-beam computed tomography (CBCT), panoramic image, and two articulator systems. Settings and Design: A cross-sectional study was carried out in 20 dentate patients in the age group of 20–40 years. Materials and Methods: Sagittal condylar guidance angles (SCGAs) were measured on two semi-adjustable articulators (Hanau Wide Vue and Denar Mark 320) using protrusive interocclusal record. SCGAs were also measured on the CBCT scans (CBCT reconstructed panoramic image and CBCT sagittal cross section) and the panoramic images obtained from the patients. The angles were determined on the radiographs by joining two lines: Frankfort’s horizontal plane and the other plane were drawn by connecting the superior-most point on the glenoid fossa and the inferior-most point on the articular eminence. All the measurements were done twice by two operators independently. Statistical Analysis Used: The data were analyzed using the paired t-test and Pearson’s correlation coefficient with a P ≤ 0.05. Results: There was no significant difference between the right and the left side in any of the groups (P ≥ 0.05). In addition, there was no significant difference between the clinical methods (P ≥ 0.05). However, there was a significant difference between the clinical and the radiographic methods (P ≤ 0.05). Furthermore, there was a strong correlation between the clinical and radiographic methods with Pearson’s Correlation coefficient above 0.67. Conclusion: There is a strong correlation between the clinical and radiographic methods. Thus, CBCT and OPG can be used an adjunct to clinical methods to record sagittal condylar guidance.

Damping Coefficient Optimization for the Articulated System of Virtual Track Trains

Virtual track trains are a new type of rail transportation because the multisection formation structure leads to more degrees of freedom of the vehicle, which may cause unstable phenomena, such as tailing, cross-swing, and folding, affecting the stability and ride comfort of the vehicle driving. To explore the effect of damping coefficient of the articulated systems on vehicle dynamics performance, a vehicle system dynamics model is established based on the actual parameters of a three-module six-axle virtual track train. According to ISO14791: 2000, select typical working conditions such as straight line, lane change, and 1/4 circle curve, and optimize the damping coefficient of the articulated systems through co-simulation. The study shows that under straight-line conditions, increasing the damping coefficient can effectively suppress the yaw angular acceleration and improve the lateral ride comfort of the vehicle but has little effect on the vertical ride comfort. Under lane change conditions, too large or small damping coefficients will deteriorate the train’s lateral stability, and a reasonable damping coefficient will improve the yaw damping ratio of the vehicle and reduce the lateral sway vibration between vehicles. Under the 1/4 circle curve conditions, the additional articulated system damper will reduce the vehicle’s curve passing performance. In this paper, the articulation stability of multimodule fully connected vehicles is analyzed and optimized for the first time, and the damping coefficient control strategy is given based on the geometric tracking control method. The research results are of great significance for the parameter selection of virtual track trains’ articulated system and the design and development of specialized articulated systems for related vehicles.

Sensory Qualities as Signs? Meyer Schapiro as a Pioneer of the Semiotics of ‘Visual Form’

The concept and nature of Form in linguistic as well as visual signs has been debated among several semioticians and art historians. Some notable analytical attempts have been put forward by Saussure, Hjelmslev, Vygotsky, and, regarding visual signs in particular, by Meyer Schapiro, Floch, Greimas, and the Groupe µ, among others. Greimas and Floch proposed a distinction between two levels of semiotic Form in visual representation, each being constitutive of a separate system of semiotic articulation: figurative language and plastic language. With arguments drawn from behavioural science, the interdisciplinary Groupe µ presented a different version of the same distinction as one between iconic and plastic signs. In this paper, I shall give a short outline of these and some further proposals, especially Meyer Schapiro’s view on the formal structure of pictures and visual signs, and his analysis of visual signifiers as ‘vehicles’ of spatial meaning. Schapiro’s account of the ‘image-sign’ will be presented as coloured by his socio-historical perspective and the empirical pragmatism of Peirce. Regarding the relationship between ‘iconic’ and ‘plastic’ meaning, Schapiro’s studies of Romanesque sculpture and non-figurative painting anticipate some observations later made by the Groupe µ. However, rather than attempting to defend any specific account of the nature of visual or plastic Form, a pluralistic position will be proposed here.

Evaluation of Precision and Reliability of Different Bite Registration Materials Using Conventional and Digital Articulator Systems

Evaluation of Precision and Reliability of Different Bite Registration Materials Using Conventional and Digital Articulator Systems

Investigating clausal wh-constructions in Romanian

Romanian has an articulated system of (non-)interrogative wh-clauses that look morphosyntactically similar or even identical to each other on the surface, while exhibiting striking differences in distribution and interpretation. Using a minimal set of criteria, tests and distinctions, this article presents the first systematic comparative overview of all clausal wh-constructions attested in Romanian. We show that none of these constructions can be reduced to any of the others and flesh out some of the challenges arising for a unified analysis of wh-constructions and wh-expressions.

Application of 3D digital smile design based on virtual articulation analysis in esthetic dentistry: A technique

A technique for the application of a virtual articulation system in 3-dimensional digital smile design (DSD) during esthetic restoration is described. To acquire stable occlusion and a smooth jaw movement pattern without premature contacts or interference, a digital facebow and a virtual articulator were used to collect and analyze a patient’s occlusal data and jaw movement information. The original pattern of occlusal contacts and jaw movements were diagnosed as stable and copied to the digital design of the new prostheses. Preparation of the abutments, crown lengthening surgery, and definitive crown fabrication and cementation were performed according to the design. After 9 months, the occlusion remained stable, and the patient was satisfied with the outcome.

Experimental Modelling of a Floating Solar Power Plant Array under Wave Forcing

Floating Photovoltaic (FPV) plants are already well developed, and deployed all over the world, on calm water inland lakes, or in sheltered locations. They are now progressing to be installed in nearshore sites, and in deep water seas. The company HelioRec, developing floating modules to form FPV arrays to be deployed in nearshore areas, was awarded free-of-charge testing of their system by the Marine Energy Alliance (MEA) European program. This paper describes the experimental testing of the 1:1 scale float system, composed of 16 floating modules supporting solar panels and three footpaths, carried out in Centrale Nantes’ ocean wave tank, allowing regular and irregular frontal and oblique wave conditions. Experimental results show that, even in the narrow wave spectrum experimentally achievable, a specific response from the array was revealed: the multibody articulated system exhibits a first-order pitch resonant mode when wavelengths are about twice the floater length. A shadowing effect, leading to smaller motions of rear floaters, is also observed, for small wavelengths only.

Three-dimensional analysis of the interchangeability of a semiadjustable articulator system in service over time

Statement of problemSome contemporary articulator systems claim to be highly precise in their interchangeability, with tolerances below 10 μm in vertical error; however, the claims have not been independently verified. PurposeThe purpose of this study was to investigate the interchangeability of calibrated semiadjustable articulators in service over time. Material and methodsA calibrated mounting articulator served as the master articulator, while the test groups were used articulators with a minimum of 1-year use by predoctoral dental students (n=10); used articulators with a minimum of 1-year use by prosthodontic residents (n=10); and new articulators (n=10). One set of mounted maxillary and mandibular master models was positioned in the master and test articulators. High-precision reference markers on the master models were used to determine interarch 3D distance distortions (dRR, dRC, and dRL), interocclusal 3D distance distortion (dRM), interocclusal 2D distance distortions (dxM, dyM, and dzM), and interocclusal angular distortion (dθM) relative to the master articulator. All measurements were conducted three times using a coordinate measuring machine and then averaged to derive the final data set. ResultsFor interarch 3D distance distortion, the mean dRR ranged from 4.6 ±21.6 μm for new articulators to 56.3 ±47.6 μm for articulators used by prosthodontic residents; mean dRC ranged from 65 ±48.6 μm for new articulators to 119.0 ±58.8 μm for articulators used by prosthodontic residents; and mean dRL ranged from 12.7 ±39.7 μm for articulators used by prosthodontic residents to 62.8 ±75.2 μm for new articulators. For interocclusal 3D distance distortion, the mean dRM ranged from 21.5 ±49.8 μm for new articulators to 68.6 ±64.9 μm for articulators used by predoctoral dental students. For the 2D distance distortions, the mean dxM ranged from −17.9 ±43.4 μm for articulators used by predoctoral dental students to −61.9 ±48.3 μm for articulators used by prosthodontic residents; mean dyM ranged from 18.1 ±59.4 μm for new articulators to 69.3 ±115.1 μm for articulators used by prosthodontic residents; and mean dzM ranged from 29.5 ±20.2 μm for new articulators to 70.1 ±37.8 μm for articulators used by prosthodontic residents. Mean dθM ranged from −0.018 ±0.289 degree for new articulators to 0.141 ±0.267 degree for articulators used by prosthodontic residents. One-way ANOVA by articulator type revealed statistically significant differences among the test groups for dRR (P=.007) and dzM (P=.011) only, where articulators used by prosthodontic residents fared significantly poorer than the other test groups. ConclusionsThe new and used articulators tested did not fulfill the manufacturer’s claim of accuracy of up to 10 μm in the vertical dimension. Up to 1 year of time in service, none of the investigated test groups fulfilled the criterion for articulator interchangeability, even if the more lenient threshold of 166 μm were accepted.

Effect of Different Lateral Condylar Guidance Registration Methods and Articulators on Bilateral Balanced Occlusion of Complete Denture

Purpose: This study was conducted to accomplish the most balanced occlusion of the complete denture through comparing between lateral condylar guidance angle records of Hanau Equation, Gothic arch tracing and Computed tomography (CBCT) using arcon and non arcon articulators. Materials and methods: Twelve completely edentulous patients were selected for this study, with age ranging from 50-60 years. Selected patients were free from any temporomandibular disorders or dental diseases. Each patient received a complete denture and then duplicated another one for work. With bilateral balanced occlusion concept. The lateral condylar guidance measured using Hanau equation calculated from protrusive interocclusal records, Gothic arch tracer and Cone beam computed tomography. All records transferred to two types of semi-adjustable articulators Hanau non arcon articulator and Bio-art arcon articulator. Denture adjusted on the both articulator system to measure and achieve the bilateral balanced occlusion. Results: In present study comparison between the three methods of right and left lateral condylar guidance registrations Hanau Equation, Cone Beam CT and Gothic arch tracing on both types of articulators shows insignificant difference between right side (p=0.443) and left side (p=0.094) of lateral condylar guidance and also the balanced occlusion values of right and left side on arcon and non arcon semi-adjustable articulator were statically non-significant. Conclusions: Within the outcomes of this study, it could be concluded that to achieve balanced occlusion of complete denture Hanau equation obtained from inter occlusal records with using of Hanau arcon semi-adjustable articulator will be recommended.

Effect of Different Lateral Condylar Guidance Registration Methods and Articulators on Bilateral Balanced Occlusion of Complete Denture

Purpose: This study was conducted to accomplish the most balanced occlusion of the complete denture through comparing between lateral condylar guidance angle records of Hanau Equation, Gothic arch tracing and Computed tomography (CBCT) using arcon and non arcon articulators. Materials and methods: Twelve completely edentulous patients were selected for this study, with age ranging from 50-60 years. Selected patients were free from any temporomandibular disorders or dental diseases. Each patient received a complete denture and then duplicated another one for work. With bilateral balanced occlusion concept. The lateral condylar guidance measured using Hanau equation calculated from protrusive interocclusal records, Gothic arch tracer and Cone beam computed tomography. All records transferred to two types of semi-adjustable articulators Hanau non arcon articulator and Bio-art arcon articulator. Denture adjusted on the both articulator system to measure and achieve the bilateral balanced occlusion. Results: In present study comparison between the three methods of right and left lateral condylar guidance registrations Hanau Equation, Cone Beam CT and Gothic arch tracing on both types of articulators shows insignificant difference between right side (p=0.443) and left side (p=0.094) of lateral condylar guidance and also the balanced occlusion values of right and left side on arcon and non arcon semi-adjustable articulator were statically non-significant. Conclusions: Within the outcomes of this study, it could be concluded that to achieve balanced occlusion of complete denture Hanau equation obtained from inter occlusal records with using of Hanau arcon semi-adjustable articulator will be recommended.

Explosive rigidity percolation in kirigami

Controlling the connectivity and rigidity of kirigami, i.e. the process of cutting paper to deploy it into an articulated system, is critical in the manifestations of kirigami in art, science and technology, as it provides the resulting metamaterial with a range of mechanical and geometric properties. Here, we combine deterministic and stochastic approaches for the control of rigidity in kirigami using the power of k choices, an approach borrowed from the statistical mechanics of explosive percolation transitions. We show that several methods for rigidifying a kirigami system by incrementally changing either the connectivity or the rigidity of individual components allow us to control the nature of the explosive transition by a choice of selection rules. Our results suggest simple lessons for the design of mechanical metamaterials.

960. Optimizing the report of antimicrobial resistance in Mexican hospitals: An unfinished business.

Abstract Background One of the aims of antimicrobial stewardship programs (ASP) in hospitals is to make an efficient use of the available infrastructure to enhance surveillance and antimicrobial resistance (AMR) reporting. In this study, we aimed to explore specific AMR reporting mechanisms in ASPs in Mexican hospitals in order to highlight potential areas of improvement. Methods An online survey was applied to a purposive sample of 40 hospitals who performed regular antimicrobial stewardship activities in Mexico. Answers regarding a subset of questions on antimicrobial susceptibility monitoring and reporting practices were provided by ASP professionals. Results A total of 39 hospitals (14 private and 25 public hospitals) in 13 states in Mexico answered the subset of the survey. Thirty-three of those (85%) expressed that their databases allowed periodically monitoring of changes in susceptibility and resistance patterns for specific pathogens. As many as 17 hospitals (44%) reported to two external national academic networks and none reported to international ones. Only 10 reported to the National Hospital Network for Epidemiological Surveillance (RHOVE) in charge of AMR data (29%). Thirty hospitals (77%) declared reporting their AMR consolidated results internally to either the epidemiology department, an ASP leader, or other hospital committee. Twenty percent of the surveyed hospitals issued AMR reports to two entities, an additional 10% of them to 3 entities and 5% more to 4 different entities; reporting to >3 entities was observed only in public hospitals. Two hospitals (5%) declared not submitting AMR reports at all. Conclusion The adoption of reporting commitments without guiding national AMR policies derives into the duplicity of processes (reporting to different networks or entities) requiring additional human and financial resources. It also reflects the unavailability of a functional national reporting system allowing all hospitals to monitor and access the reported information nationally or internationally (GLASS). Optimizing AMR surveillance and reporting in Mexico must incorporate the simplification and standardization of reporting processes into an articulated system in line with the National Strategy against AMR. Disclosures Anahí Dreser, PhD, MSD: Grant/Research Support.

Investigation of a Cabin Suspended and Articulated Rescue Vessel in Terms of Motion Reduction

To solve the problem that small rescue vessels are seriously affected by waves when working at sea, which causes damage to the crew and equipment, a catamaran with a suspended and articulated cabin is designed. The multi-body dynamic model of the whole vessel based on SimMechanics is built, and the prototype is tested on the water. The correctness of the model is verified based on the three aspects of the roll motion, pitch motion, and heave motion of the rescue platform. The motion of the rescue platform is simulated under the conditions of bow waves and large heave waves, and the RMS value of the vertical acceleration of the rescue platform is taken as the response target to analyze the influence of the suspension system parameters of the whole vessel. The suspension system has good buffering and motion reduction effects under various working conditions, and it has an obvious reduction effect on the vertical acceleration at the rescue platform. The larger the amplitude of the wave impact, the more obvious the effect. The articulated system reduces the roll angle and the heave amplitude under the conditions of bow waves.

Experimental Closed-Loop Excitation of Nonlinear Normal Modes on an Elastic Industrial Robot

Adding elastic elements to the mechanical structure should enable robots to perform efficient oscillatory tasks. Still, even characterizing natural oscillations in nonlinear systems is a challenge in itself, which nonlinear modal theory promises to solve. Therein eigenmanifolds generalize eigenspaces to mechanical systems with non-Euclidean metrics and thus characterize families of oscillations that are autonomous evolutions of the robot. Eigenmanifolds likewise provide a framework for deriving feedback controllers to excite and sustain these oscillations. Nevertheless, these results have been so far essentially theoretical. They have been applied on relatively low dimensional systems and almost exclusively in simulation. We aim to bridge the theory to the real-world gap with the present work and show that we can excite nonlinear modes in complex systems. To this end, we propose control strategies that can simultaneously stabilize numerically evaluated eigenmanifolds and sustain oscillations in the presence of dissipation. We then focus on the KUKA iiwa with simulated parallel springs as an example of the highly nonlinear and articulated system. We calculate all the nonlinear modes of the system, and we use the proposed strategies to excite the associated natural oscillations.

Digital restoration of the pectoral girdles of two Early Cretaceous birds and implications for early-flight evolution

The morphology of the pectoral girdle, the skeletal structure connecting the wing to the body, is a key determinant of flight capability, but in some respects is poorly known among stem birds. Here, the pectoral girdles of the Early Cretaceous birds Sapeornis and Piscivorenantiornis are reconstructed for the first time based on computed tomography and three-dimensional visualization, revealing key morphological details that are important for our understanding of early-flight evolution. Sapeornis exhibits a double articulation system (widely present in non-enantiornithine pennaraptoran theropods including crown birds), which involves, alongside the main scapula-coracoid joint, a small subsidiary joint, though variation exists with respect to the shape and size of the main and subsidiary articular contacts in non-enantiornithine pennaraptorans. This double articulation system contrasts with Piscivorenantiornis in which a spatially restricted scapula-coracoid joint is formed by a single set of opposing articular surfaces, a feature also present in other members of Enantiornithines, a major clade of stem birds known only from the Cretaceous. The unique single articulation system may reflect correspondingly unique flight behavior in enantiornithine birds, but this hypothesis requires further investigation from a functional perspective. Our renderings indicate that both Sapeornis and Piscivorenantiornis had a partially closed triosseal canal (a passage for muscle tendon that plays a key role in raising the wing), and our study suggests that this type of triosseal canal occurred in all known non-euornithine birds except Archaeopteryx, representing a transitional stage in flight apparatus evolution before the appearance of a fully closed bony triosseal canal as in modern birds. Our study reveals additional lineage-specific variations in pectoral girdle anatomy, as well as significant modification of the pectoral girdle along the line to crown birds. These modifications produced diverse pectoral girdle morphologies among Mesozoic birds, which allowed a commensurate range of capability levels and styles to emerge during the early evolution of flight.

MU’JAM LUGHAWIY DAN PEROBLEMATIKA PENGGUNAANNYA DALAM PEMBELAJARAN BAHASA ARAB PADA MAHASISWA DI KOTA BIMA

Mu'jam Lughawiy has crucial or even inseparable uses. Mu'jam Lughawiy has become a favorite tool for language learners. especially when faced with activities to find the meaning of a word. grammar. or the context of its use in the desired language. History also records that Mu'jam Lughawiy went through several stages of development. both in terms of its composition and the systematics of its writing along with its pluses and minuses. So therefore. This paper seeks to identify the problems faced by students in Bima City when using Mu'jam Lughawiy in learning Arabic. This paper can contribute positively to educators. learners. as well as foreign language practitioners, especially Arabic as initial information related to the problems faced by students when using Mu'jam Lughawiy so that they can be used as references in finding alternative solutions to various obstacles encountered when interacting with Mu'jam Lughawiy. This study applies a qualitative approach through the case study method and uses semi-structural interviews as a data collection technique and thematic analysis methods as a data analysis technique that has been obtained. In determining students as participants. The author applies a purposive sampling technique based on the student population at Islamic Higher Education in the City of Bima. This paper concludes that students' problems when using Mu'jam Lughawiy in Arabic learning are dominated by linguistic factors due to weak grammatical abilities as a result of weak learning motivation and problems in the Arabic learning process at the previous level. Students are more interested in interacting with Mu'jam Lughawiy in the form of software that uses an articulation system because of the financial efficiency factor.

Deep Measurement Updates for Bayes Filters

Measurement update rules for Bayes filters often contain hand-crafted heuristics to compute observation probabilities for high-dimensional sensor data, like images. In this work, we propose the novel approach Deep Measurement Update (DMU) as a general update rule for a wide range of systems. DMU has a conditional encoder-decoder neural network structure to process depth images as raw inputs. Even though the network is trained only on synthetic data, the model shows good performance at evaluation time on real-world data. With our proposed training scheme primed data training , we demonstrate how the DMU models can be trained efficiently to be sensitive to condition variables without having to rely on a stochastic information bottleneck. We validate the proposed methods in multiple scenarios of increasing complexity, beginning with the pose estimation of a single object to the joint estimation of the pose and the internal state of an articulated system. Moreover, we provide a benchmark against Articulated Signed Distance Functions(A-SDF) on the RBO dataset as a baseline comparison for articulation state estimation.

Current trends in the treatment of acetabular fractures (literature review)

Acetabular fractures are known for their disabling outcomes, so the search for optimal treatment tactics is an actual problem for modern orthopedics and traumatology. Materials and methods. Randomized trials that reflect the results of acetabular fractures treatment depending on the method of treatment were analyzed. The literature was searched in the PubMed Central database. Hip joint is a complex two-component articulated system. Traumatic lesion of all elements of the joint creates the conditions for the development of a wide range of complications and secondary changes that must be taken into account at preoperative treatment. Aceta­bular fracture is an intra-articular injury, where the visualization methods have the prominent significance. Nowadays the treatment can be conservative and surgical. Surgical treatment can be divided into two areas: osteosynthesis and arthroplasty. Anatomical reposition and stable fixation of fragments, in the most of cases, is the key to a satisfactory functional result, but the development of post-traumatic changes in the joint nullifies the results of even perfect osteosynthesis, encourages repeated surgery and, finally, hip replacement. In recent years, primary arthroplasty has been successfully used to treat acetabular fractures, reducing inpatient and rehabilitation period, compared with osteosynthesis, preventing the possible development of secondary degenerative changes in the joint. Conclusions. Acute hip replacement is an effective treatment, however, the technical aspects of reliable fixation of the ace­tabular component of the implant are insufficiently substantiated and highlighted in actual literature and constitute significant research interest.