Constrained liners, dual mobility or large diameter heads to avoid dislocation in THA.

Dislocation remains a common cause of failure after total hip arthroplasty. The limitations of existing approaches to address instability have led to the development of powerfull options: constrained liners, dual mobility and large heads. These implant-related options have proven to be very efficient, but have raised concerns.With constrained liners, restricted range of motion (ROM) is responsible for impingement leading to high likelihood of failure, depending on the design, with various failure modes.Improvements of the bearing materials have addressed some of the concerns about increased volumetric wear of conventional polyethylene and offer an option to reduce instability: large diameter heads have the advantage of increased ROM before impingement, increased head-neck ratio, and jump distance. Highly cross-linked polyethylene helps address the risk for increased wear, and also large heads provide improved stability without the risk of mechanical failures observed with constrained liners. However, the increase of the head size remains limited as reducing the thickness of the liner may lead to fractures. In addition, the jump distance decreases as the cup abduction increases.The dual mobility concept simultaneously attempts to address head-neck ratio, constraint, and jump distance. Despite the need for longer follow-up, concerns raised about potential increased wear and intra-prosthetic dislocation with first generation implants have been addressed with modern designs.With a dramatic increase of the head-neck ratio whilst reducing the risk of mechanical failure or excessive wear, dual mobility THA outperforms large diameter heads and constrained liners at 10 years follow-up. For these reasons, dual mobility continues to gain interest worldwide and is becoming the most popular option to manage instability. Cite this article: Guyen O. Constrained liners, dual mobility or large diameter heads to avoid dislocation in THA. EFORT Open Rev 2016;1:197-204. DOI: 10.1302/2058-5241.1.000054

Analisa Tegangan New Critical Line Pipe dari Discharge Compressor Scrubber Train menuju Tie In Point Existing MP Gas Scrubber Pipe pada Sistem CO2 Removal Di Fasilitas Produksi Cilamaya Utara

North Cilamaya Station is a plant to receive production which comes from the structure of North Cilamaya (CLU), East Cilamaya (CLT) and Bambu Gunung (BBU), so that additional production facilities are needed in North Cilamaya. One of the facilities piping system that connects Discharge Compressor Scrubber Train to Tie in point. This pipeline has 6 line numbers diameter of 6" and 10" with a design temperature of 350° F, therefore the load and expansion of heat received by the pipe is very large so that it needs proper calculations and simulations. Stress analysis in this final project focuses on static stress analysis and flexibility of the pipe which includes stress due to sustained load, thermal load, and nozzle load. From the above problems analyzed by comparing manual calculation with running results on CAESAR II software so that the stress value can be determined according to the limits of ASME B31.3. The results of manual calculations and CAESAR II software show the sustained loads, thermal loads and nozzle loads on the piping system is below the allowable limit value. So, from the results of the manual calculations or CAESAR II software states that the piping system is safe when operating

3-[4-(10H-Indolo[3,2-b]quinolin-11-yl)piperazin-1-yl]propan-1-ol

In the title compound, C22H24N4O, the aromatic moiety is essentially planar (r.m.s. deviation of a least-squares plane fitted through all non-H atoms = 0.0386 Å) and is rotated by 89.98 (4)° from the piperazine ring, which adopts the expected chair conformation. The propanol chain is not fully extended away from the piperazine ring. In the crystal, there are two unique hydrogen-bonding inter­actions. One is an O—H⋯N inter­action which, together with an inversion-related symmetry equivalent, forms a ring motif. The second is an N—H⋯N inter­action which links adjacent mol­ecules by means of a chain motif which propagates in the c-axis direction. Overall, a two-dimensional hydrogen-bonded structure is formed

Использование препаратов магния в комплексной терапии атопического дерматита

Обоснована необходимость нормализации баланса магния и кальция крови при атопическом дерматите, изучено действие метаболического препарата магнерот при этом заболевании. Показано, что применение магния оротата в комплексном лечении дерматоза способствует улучшению клинического течения болезни и нормализации большинства лабораторных показателей. Полученные результаты свидетельствуют о патогенетической обоснованности препаратов, содержащих магний, в лечении атопического дерматита.The necessity to normalize the balance of the blood magnesium and calcium in atopic dermatitis was substantiated. The effect of Magnerot (a metabolic medication) in this disease was investigated. The use of magnesium orotate in complex treatment of the dermatosis was shown to improve the clinical course of the disease and normalize the majority of the laboratory findings. The obtained findings suggest that the use of magnesium−containing medication in treatment of atopic dermatitis is pathogenetically substantiated

High failure rate of the Duraloc Constrained Inlay

Background and purpose After total hip arthroplasty, dislocations are a frequent complication and are difficult to treat in some patients. A great variety of implants and antiluxation mechanisms are used in surgical therapy

Moduli Spaces for Four- and Five- Dimensional Black Holes

We propose a universal expression for the moduli metric of a class of four- and five-dimensional black holes which preserve at least four supersymmetries. These include the black holes that are associated with various intersecting branes in ten and eleven dimensions, the electrically charged black holes of N=2 D=5 and N=2 D=4 supergravities with any number of vector multiplets, and dyonic black holes of N=2 D=4 supergravity. The moduli metric of electrically charged N=2 D=4 black holes coupled to any number of vector multiplets is explicitly computed. We also investigate the superconformal symmetries of the black hole moduli spaces for small black hole separations.Comment: 44 pages, phyzzx.tex, minor corrections, some more references adde

Effect of friction and clearance on kinematics and contact mechanics of dual mobility hip implant.

The dual mobility hip implant has been introduced recently and increasingly used in total hip replacement to maintain the stability and reduce the risk of post-surgery dislocation. However, the kinematics and contact mechanisms of dual mobility hip implants have not been investigated in detail in the literature. Therefore, finite element method was adopted in this study to investigate dynamics and contact mechanics of a typical metal-on-polymer dual mobility hip implant under different friction coefficient ratios between the inner and the outer articulations and clearances/interferences between the ultra-high-molecular-weight polyethylene liner and the metal back shell. A critical ratio of friction coefficients between the two pairs of contact interfaces was found to mainly determine the rotating surfaces. Furthermore, an initial clearance between the liner and the back shell facilitated the rotation of the liner while an initial interference prevented such a motion at the outer articulating interface. In addition, the contact area and the sliding distance at the outer articulating surface were markedly greater than those at the inner cup-head interface, potentially leading to extensive wear at the outer surface of the liner