Porous Components Research Articles

Interparticle photo-cross-linkable Pickering emulsions for rapid manufacturing of complex-structured porous ceramic materials

A new series of Pickering emulsions that can be photo-cured by interparticle photo-cross-linking reactions using small amounts of multifunctional acrylate (MA) monomers is proposed to rapidly manufacture complex-structured porous ceramic materials. In our new process, water in oil (w/o) Pickering emulsion was designed by vigorous mixing of water and polyethyleneimine partially complexed with oleic acid (PEI–OA)-stabilized SiO2/toluene suspension containing small amounts of MA and a photo-radical initiator. Ultraviolet light irradiation to this w/o Pickering emulsion induced the formation of interparticle photo-crosslinks, which resulted in successful photocuring by photo-radical polymerization of MA and the Michael addition reaction between the polymerized MA and PEI–OA on the particles in the oil phase. We further applied the newly designed photo-curable Pickering emulsion and demonstrated that SiO2 components with pores related to the dispersed aqueous phase and complexed outer structures could be shaped via silicone molding or a hybridized approach of photocuring and green machining. Because of the reduced amounts of MA used, the porous SiO2 green components could be heat-treated using rapid heating profiles without any structural collapse for dewaxing and partial sintering.

Hydrophobically/oleophilically guarded powder metallurgical structures and liquid impregnation for ice mitigation

Icing hazards often pose operational and safety challenges. Various surface and coating approaches have been attempted for ice mitigation purposes, but the durability remains an outstanding issue. Inspired by traditional powder metallurgy and slippery icephobic surfaces, a new strategy for slippery liquid-impregnated porous metallic structure (LIPMS) with gradient porosity was proposed in this study for ice mitigation, by directly impregnating selected liquids into sintered porous copper components with hydrophobic/oleophilic guarding consideration. The results indicated that robust LIPMS with desired porosity were obtained, significantly delaying the icing of surface water droplets, providing good frost resistance in a high humid environment, and demonstrating ultra-low ice adhesion strength (less than 1 kPa). It was confirmed that the hydrophobic/oleophilic guarding design significantly improved icephobic durability, attributing to its role in repelling external water and maintaining internal slippery liquid. To offer a comprehensive understanding of icephobic mechanisms and the potentials of LIPMSs, a concept of ice initiation position was also proposed and theoretically discussed. The pivotal factor of icephobic LIPMS is to maintain the icing initiation position at the unfrozen liquid–liquid interface or inside the homogeneous liquid, thus inhibiting icing and facilitating the ice removal.

Characterisation and modelling of water wicking and evaporation in capillary porous media for passive and energy-efficient applications

Passive devices based on water wicking and evaporation offer a robust, cheap, off-grid, energy-efficient and sustainable alternative to a wide variety of applications, ranging from personal thermal management to water treatment, from filtration to sustainable cooling technologies. Among the available, highly-engineered materials currently employed for these purposes, polyethylene-based fabrics offer a promising alternative thanks to the precise control of their fabrication parameters, their light-weight, thermal and mechanical properties, chemical stability and sustainability. As such, both woven and non-woven fabrics are commonly used in capillary-fed devices, and their wicking properties have been extensively modelled relying on analytical equations. However, a comprehensive and flexible modelling framework able to investigate and couple all the heat and mass transfer phenomena regulating the water dynamics in complex 2-D and 3-D porous components is currently missing. This work presents a comprehensive theoretical model aimed to investigate the wetting and drying performance of hydrophilic porous materials depending on their structural properties and on the external environmental conditions. The model is first validated against experiments (R2=0.99 for the wicking model; errors lower than 14% and 1% for the evaporation and radiative models, respectively), then employed in three application cases: the characterisation of the capillary properties of a novel textile; the assessment of the thermal performance of a known material for personal thermal management when used in different conditions; the model-assisted design of a porous hydrophilic component of passive devices for water desalination. The obtained results showed a deep interconnection between the different heat and mass transfer mechanisms, the porous structure and external working conditions. Thus, modelling their non-linear behaviour plays a crucial role in determining the optimal material characteristics to maximise the performance of porous materials for passive devices for the energy and water sector.

Measurement of safe acetabular medial wall defect size in revision hip arthroplasty with a porous cup.

The majority of acetabular revisions can be performed with an uncemented, porous acetabular component with or without bone grafting. These are contained acetabular defects, with an intact acetabular rim (Paprosky type I and II). As defects of the medial wall of the acetabulum are a challenge situation revision surgery, we performed this biomechanical study on a pig pelvis model with contained acetabular defects to determine the size of medial wall defect at which the acetabular cup will have sufficient primary stability. In 24 pig pelvis models, different diameter of medial wall defects were created, followed by acetabular component placement. The acetabulum externally loaded, and the force at a level in which the acetabular component remains stable for each diameter of defect, or at which point the acetabular cup moves into the pelvis for >2 mm. In the models with acetabular medial wall defects of 10 and 20 mm, 2 mm acetabular displacement occurred under a force between 1000 and 1500 N. In those with a medial wall defect of 25 mm, the force that caused acetabular instability was between 700 and 1000 N. In the models with 30 mm of medial wall defect all acetabular components were unstable under a force of 700 N. According to our results, acetabular component should be stable if the defect of the medial wall of the acetabulum is less than 68% of the diameter of the acetabular component or if the uncovered surface area of the acetabular component is not greater than 27%, and the force <700 N. For a load of 1000 N, the medial wall defect should not exceed 45% of acetabular component diameter or 18% of uncovered acetabular component surface.

Total Knee Replacement with an Uncemented Porous Tantalum Tibia Component: A Failure Analysis.

Porous tantalum has been extensively used in orthopaedic surgery, including uncemented total knee arthroplasty (TKA). Favourable results were reported with earlier monobloc tibial components and the design evolved to modular implants. We aimed to analyse possible causes for extensive medial tibia bone loss, resulting in modular porous tantalum tibia baseplate fracture after primary TKA. Retrieved tissue samples were scanned with 3 MeV focused proton beam for Proton-Induced X-ray Emission (micro-PIXE) elemental analysis. Fractographic and microstructural analysis were performed by stereomicroscopy. A full 3D finite-element model was made for numerical analysis of stress–strain conditions of the tibial baseplate. Histological examination of tissue underneath the broken part of the tibial baseplate revealed dark-stained metal debris, which was confirmed by micro-PIXE to consist of tantalum and titanium. Fractographic analysis and tensile testing showed that the failure of the tibial baseplate fulfilled the criteria of a typical fatigue fracture. Microstructural analysis of the contact surface revealed signs of bone ingrowth in 22.5% of the surface only and was even less pronounced in the medial half of the tibial baseplate. Further studies are needed to confirm the responsibility of metal debris for an increased bone absorption leading to catastrophic tibial tray failure.

REVERSE SHOULDER ARTHROPLASTY. HISTORY AND DEVELOPMENT PROSPECTS

In elderly patients with a low bone mineral density primary endoprosthesis shoulder joint is one of the methods of surgical treatment. Goal. Perform a historical review of the development of reverse shoulder arthroplasty (RSA) with analysis of biomechanical features of existing implants, their advantages and disadvantages to identify possible areas for further ways of improvement. Methods. Search for scientific information was performed in electronic databases PubMed, ScienceDirect, Google Scholar with a search depth of 30 years. There were selected 68 sources. Results. Unsatisfactory results after shoulder hemiarthroplasty caused in patients with severe damage to the rotator cuff and multifragmental fractures of the proximal humerus using RSA. Endoprosthesis design C. Neer replaced the implants of P. Grammont design, built on the principles: spherical glenoid component, concave support part on the humerus, the center of rotation at the level or medially of the scapular neck, proximal humerus fractures is displaced medially and distally. Medialization of the center of rotation is anunfavorable factor that leads to loss of tension of the deltoid muscle. To eliminate this disadvantages, lateralized hemispheres have been developed, with the help of which stability is achieved, the formation of a defect of the lower edge of the scapular neck is prevented. Their size affects on the volume of movements: the smallest diameters should be used for prevention of soft tissue strain. Note that the use of RSA with a lateralized center of rotation and varus shoulder component brings biomechanics closer shoulder joint to normal anatomical features. Conclusions. The main directions of RSA improvement: conducting biomechanical research to evaluate structures endoprostheses in order to choose the optimal design; introduction of modern additive technologies that will allow to obtain porous components with increased osteointegrative properties; reduce the weight of the hemisphere; improving friction pairs

Revision for Aseptic Loosening of Highly Porous Acetabular Components in Primary Total Hip Arthroplasty: An Analysis of 20,993 Total Hip Replacements.

Highly porous-coated titanium acetabular components have a high coefficient of friction and ultraporous surfaces to enhance bone ingrowth and osseointegration in total hip arthroplasty (THA). There have been concerns with the development of early radiolucent lines and aseptic loosening of highly porous acetabular components. It is unclear whether these concerns relate to a specific implant or the entire class. The aim of this study is to compare the revision rates for aseptic loosening of highly porous acetabular combinations in primary THA using data from a large joint replacement registry. Data were retrieved from the Australian Orthopedic Association National Joint Replacement Registry for the study period September 1999 to December 2019. All primary THA procedures recorded and performed for osteoarthritis using the most common combinations for each highly porous acetabular component with highly cross-linked polyethylene and a 32-mm or 36-mm femoral head were included. The primary outcome measure was revision for aseptic loosening of the acetabular component. Results were adjusted for patient age and gender. There were 20,993 primary THA procedures performed for osteoarthritis using a highly porous acetabular component across 6 combinations. Relative to the POLARSTEM/R3 (StikTite), the Exeter V40/Tritanium had a significantly higher risk of revision for aseptic loosening of the acetabular component (hazard ratio 0.21, 95% confidence interval 0.06-0.74, P= .014). There was no difference between any other highly porous acetabular component combination and no late revisions for aseptic loosening. Highly porous-coated titanium acetabular components have low rates of aseptic loosening with long-term follow-up. A difference between components may exist. Level III.

Hydrodynamic Performance of A Porous-Type Land-Fixed Oscillating Water Column Wave Energy Converter

A hybrid, porous breakwater—Oscillating Water Column (OWC) Wave Energy Converter (WEC) system is put forward and its hydrodynamic performance is investigated using the fully nonlinear, open-source computational fluid dynamics (CFD) model, OpenFOAM. The permeable structure is positioned at the weather side of the OWC device and adjoined to its front wall. A numerical modelling approach is employed in which the interstices within the porous structure are explicitly defined. This permits the flow field development within the porous structure and at the OWC front wall to be observed. The WEC device is defined as a land-fixed, semi-submerged OWC chamber. A range of regular incident waves are generated at the inlet within the numerical tank. The OWC efficiency and the forces on the structure are examined. Results are compared for the simulation cases in which the porous component is present or absent in front of the OWC chamber. It is found that the incorporation of the porous component has minimal effect on the hydrodynamic efficiency of the OWC, reducing the efficiency by less than 5%. Nevertheless, the forces on the front wall of the OWC can be reduced by up to 20% at the higher wave steepness investigated, through inclusion of the porous structure at the OWC front wall. These findings have considerable implications for the design of hybrid OWC—breakwater systems, most importantly in terms of enhancing the durability and survivability of OWC WECs without significant loss of operational efficiency.

A parametric study on the performance requirements of key fuel cell components for the realization of high-power automotive fuel cells

This study examined the performance limitations of polymer electrolyte membrane fuel cells (PEMFC) for high power operations. The effects of improving electron, heat, and oxygen transport within a PEMFC on the cell performance were investigated using a three-dimensional, multiscale, two-phase PEMFC model. For more realistic PEMFC simulations at high current densities, the model newly accounts for anisotropic electron and heat transport in porous components of the membrane electrode assembly (MEA) and the non-uniform MEA compression/deformation occurring during PEMFC stack assembly. The simulations revealed improved transport properties that can be realized by optimizing the component material and design, and the degree of performance improvement was examined for a wide range of operating current densities up to 3.0 A/cm2. The simulations showed that improving the through-plane electronic conductivity and thermal conductivity of MEA components is critical for achieving high-power PEMFC performance. By contrast, the properties of the cathode catalyst layer, such as the Pt particle size and oxygen permeation rate through the ionomer film, are relatively less important under high current density PEMFC operations.

Water Management for of Proton Exchange Membrane Fuel Cells Marketing and Sensitive Balance

Electromembrane processes are a significant component of electrochemical technology. Now it is well accepted that the performance and durability of proton exchange membrane fuel cells (PEMFCs) are inextricably linked to the buildup and transit of water inside their porous components, notably the gas diffusion layer (GDL) and microporous layer. In this paper, the electroosmotic drag in membranes and water management which is the chief difficulty facing the membrane are discussed and a review of the mechanism of transport and membrane water transport with sorption/desorption are presented.

Medial peg position of cementless porous tantalum tibial component affects bone mineral density around the prosthesis after total knee arthroplasty: 2-year follow-up study

BackgroundUse of a porous tantalum tibial component for total knee arthroplasty (TKA) was reported to have beneficial effects on periprosthetic bone mineral density (BMD). In some cases, hexagonal peg is placed close to or in contact with the tibial cortex, which may result in stress-shielding around the peg. However, no studies have analyzed the relationship between peg position and BMD. The aim of this study was to compare the peg position and BMD around the peg in a porous tantalum tibial component after TKA. MethodsTwenty-seven patients (27 knees) who underwent primary TKA with a cementless porous tantalum tibial component were investigated. BMD was measured by dual-energy X-ray absorptiometry for 2 years after the operation. The distance between the peg and the tibial cortex (peg distance) was measured on the medial and lateral sides. ResultsBMD was decreased in the medial region after the operation (p < 0.01). Relative change in BMD was lower in the medial region than in the central and lateral regions (p < 0.01). Multiple regression analysis showed that medial peg distance was negatively correlated with relative change of BMD in the medial part of the tibia (p = 0.04, R = 0.402). ConclusionsThe medial peg position affected the postoperative relative change of BMD in the medial part of the tibia, but did not affect the longevity of the implant. As the tibial medial peg became closer to the medial tibial cortex, the BMD loss became larger in the medial part of the tibia at 2 years postoperatively.

Blast mitigation properties of porous nano-carbon

Designing and development of a superior shock mitigation nano–material shield is an emerging armour building technology. We report, the effect of Kolsky bar simulated blast waves, onto the shock damping characteristics of the porous nano–carbon (abbreviation: PNC), synthesized by pyrolysis of biomass precursor. Measurement of stress (σ)–strain (ε), constitutive variables reveal the elasto–plastic behaviour suggesting moderate built–up, and accumulation of stress; independent of applied strain before reaching a yield ~50 MPa. Gruneisen fatigue parameter is estimated to be less (~0.92) over a theoretical Rayleigh limit with >80% post impact damage of porous component. The loci of dictated shock states derived from Rankine–Hugoniot formulism demonstrates the hydrodynamic interplay between pressure (P), volume (V), shock (US) and particle (UP) velocity. For PNC, Rayleigh slope is observed to be reduced, whereas, US became pressure independent over 10 GPa. Behaviour of P–UP hydrodynamic equation displays 30% variation in shock states and predicts a reduction of sound speed by a factor of ~0.25 in porous matrix. Behind the shock wavefront, matrix particles attend a max–speed of 100 km–s−1. The value of elastic limit for PNC is ~8.62 GPa as obtained by analysing the actual shock profile, with an evidence of phase transformation. Electron and force microscopy studies show reduction in an area, effectively, by 20–30%, thickness by six–fold factors with a rise in topological disorder. Hydro–physical variables inferred from Raman, scanning electron, transmission electron, and atomic force microscopy is comparatively discussed for PNC and other nano–carbons. Shock topology obtained by pressure–time signal processing shows ~30% impact of the shock onto PNC and manifested as shock echo. Details of the analysis are presented.

Design optimization of multi-functional building envelope for thermal insulation and exhaust air heat recovery in different climates

Exhaust air insulation wall (EAIW) utilizes the exfiltration process of low-grade exhaust air within porous material to improve the thermal insulation of wall. Previous studies tend to neglect the pressure loss of exfiltration process and its impact on optimal design of EAIW. This paper quantitatively estimates the pressure loss of exfiltration process and proposes a methodology to determine the optimal design for maximizing energy saving potential of EAIW. In this study, a network heat transfer model was validated and used to calculate the hourly cooling and heating load of EAIW. The pressure loss of exfiltration process and its related energy consumption was estimated by Darcy's law . The optimal design was identified for minimizing the overall annual energy consumption of EAIW in different climates. Influences of exfiltration velocity and porous material selection on the optimal design of EAIW were investigated. The results demonstrate the pressure loss of exfiltration process significantly affects the overall energy performance and optimal design of EAIW. The optimal thickness of porous material component are 40 mm, 50 mm, and 50 mm for three climate zones, which correspond to a minimum annual overall energy consumption of 0.51 kWh/m 2 , 0.48 kWh/m 2 , and 0.49 kWh/m 2 , respectively. The porous materials with high permeability and thermal resistance are recommended as air-permeable component of EAIW. The optimal design can achieve a trade-off between cooling/heating energy consumption and fan power consumption for maximizing the energy saving potential of EAIW. • Optimal design of exhaust air insulation wall in three climates was investigated. • Pressure loss of exfiltration process through porous material was identified. • Optimal design achieves a trade-off for maximizing energy saving potential. • Permeability of porous material significantly affects the optimal design of wall.

Growth characteristics and properties of micro-arc oxidation coatings on AlSi10Mg selective laser-melted components

Micro-arc oxidation (MAO) ceramic coatings were prepared on porous AlSi10Mg selective laser-melted components to improve their corrosion property. The microstructure and composition of the coatings at different processing times were characterized via scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. Results showed that the diameter of micro-pores increased with an extension of treatment time, the porosity of coatings decreased from 6.24% to 0.85%. Thickness increased from 4.45 ± 0.01 μm to 15.20 ± 0.01 μm and surface roughness increased from 0.76 ± 0.01 μm to 5.41 ± 0.01 μm with increasing processing time. Meanwhile, the coatings were mostly composed of γ-Al2O3 and trace amounts of α-Al2O3, Al2SiO5, AlPO4 and WO3, the content of α-Al2O3 was increased from 0.51% to 4.12%. Corrosion current density decreased from 2.213 e−5 A·cm−2 to 1.088 e−7 A·cm−2. The polarization resistances Rb were increased from 4.8 × 103 Ω·cm2 to 2.6 × 105 Ω·cm2. The long term EIS results show that Rb was 7.7 × 103 Ω·cm2 after 3 weeks immersion, which show that the MAO coatings could provide good protection on AlSi10Mg alloy. The gas holes and defects of the SLM components were treated via MAO to form uniform MAO coatings on the surface of a sample, expanding the application range of selective laser-melted components in corrosive environments.

Surface Zeta Potential of ALD-Grown Metal-Oxide Films

Membranes are among the most promising technologies for energy-efficient and highly selective separations, and the surface-charge property of membranes plays a critical role in their broad applications. Atomic layer deposition (ALD) can deposit materials uniformly and with high precision and controllability on arbitrarily complex and large substrates, which renders it a promising method to tune the electrostatics of water/solid interfaces. However, a systematic study of surface-charge properties of ALD-grown films in aqueous environments is still lacking. In this work, 17 ALD-grown metal-oxide films are synthesized, and a comprehensive study of their water stability, wetting properties, and surface-charge properties is provided. This work represents a resource guide for researchers and ultimately for materials and process engineers, seeking to tailor interfacial charge properties of membranes and other porous water treatment components.

Numerical Brazilian disk testing of multiscale porous Ultra-High Temperature Ceramics

Recent developments in Ultra-High Temperature Ceramics (UHTC) processing have allowed for the introduction of significant amounts of porosity into these materials. These developments have widened the scope for how UHTCs can be integrated into hypersonic vehicles. Functional grading of porosity allows density and thermal conductivity to be spatially tailored to minimize weight penalty while maintaining thermal shielding and resilience to thermal shock. However, added porosity also results in decreased stiffness and strength. These relationships must be quantified in order to enable porous UHTC component design. In this work, a multiscale computational model using a quasi-static Material Point Method (MPM) implementation is used to quantify the mechanical response of porous UHTCs subject to Brazilian disk testing. The as-implemented MPM algorithm can readily handle large deformations, self-contact and damage. Microscale simulations corresponding to a range of strain states are simulated to calibrate an effective macroscale damage model for use in the macroscale Brazilian disk test simulations. A variety of mesoscale property distributions are considered and used in an initial effort to validate the multiscale modeling approach developed herein, with results closely matching experimental findings after model calibration at the mesoscale.

Up-Cycling of LCD Glass by Additive Manufacturing of Porous Translucent Glass Scaffolds

Additive manufacturing technologies, compared to conventional shaping methods, offer great opportunities in design versatility, for the manufacturing of highly porous ceramic components. However, the application to glass powders, later subjected to viscous flow sintering, involves significant challenges, especially in shape retention and in the achievement of a substantial degree of translucency in the final products. The present paper disclosed the potential of glass recovered from liquid crystal displays (LCD) for the manufacturing of highly porous scaffolds by direct ink writing and masked stereolithography of fine powders mixed with suitable organic additives, and sintered at 950 °C, for 1–1.5 h, in air. The specific glass, featuring a relatively high transition temperature (Tg~700 °C), allowed for the complete burn-out of organics before viscous flow sintering could take place; in addition, translucency was favored by the successful removal of porosity in the struts and by the resistance of the used glass to crystallization.

Fabrication of porous PZT ceramics using micro-stereolithography technology

Based on micro-stereolithography (μSL) additive manufacturing (AM) followed by the use of the burnable plastic sphere (BURPS) technique, we present the fabrication of porous lead zirconate titanate (PZT) ceramics. A printing slurry was prepared by mixing photocurable ceramic suspensions with various contents of polymethylmethacrylate (PMMA) as a pore-forming agent (PFA). We found that the cure depth increased gradually with increasing PMMA content. The sintered PZT ceramics exhibited a porous microstructure of predominantly spherical pores formed by PMMA, with sizes ranging from ~15 to 35 μm. The porosity of the PZT ceramics increased from 11.3% to 21.9%, corresponding to a decrease in the density from 6.92 to 6.09 g/cm3 due to the increasing PMMA content. As the porosity increased, the acoustic impedance decreased from 24.4 to 12.6 MRayls (106 kg/m2 s). The porous PZT ceramic with 5 wt% PMMA exhibited superior dielectric and piezoelectric properties (d33 = 525 pC/N, εr = 2417, tanδ = 0.04) that were comparable to those of ceramics fabricated by conventional methods. These results suggest that μSL technology is a viable alternative for fabricating porous PZT ceramic components, especially pieces with complex geometric structures.

Buckling responses of porous structural components with gradient power-based and sigmoid material variations under different types of compression loads

This work developed a comprehensive finite element model and numerical studies to illustrate the effect of porosity parameter on critical buckling responses of functionally graded power-based and sigmoid plates and spherical caps subjected to various types of edge compression loads, for the first time. The model, which follows the kinematics of the first-order-shear deformation theory (FSDT) in many aspects, accounts for a quadratic variation of the transverse shear strains and satisfy the zero condition of the transverse shear stresses at the upper and bottom surfaces of the structure without using shear correction factors. Due to lack of investigations on buckling analysis of porous FGM structures and notably for spherical cap shells, we provide new buckling results for porous FGM structures with evenly and unevenly porosity distributions. The influences of functionally graded index, porosity coefficient, porosity patterns, geometrical design parameters and boundary conditions are investigated and presented in a new graphic manner. The recommended model is helpful for predicting and controlling of the buckling behavior of porous FGM structures used in nuclear and aeronautical sectors where the safety of the engines is a crucial criterion.

Multicup reconstruction technique for the management of severe protrusio acetabular defects

BackgroundIn revision hip arthroplasty, managing the large protrusio acetabular defects remains a challenge. The report described a novel technique which employs a trabecular metal revision shell as a super-augment to buttress the superior medial structure.MethodsBetween January 2015 and December 2018, the multicup reconstruction was performed in 21 patients with severe protrusio acetabular defects. The revision shell, plus two similar porous acetabular components was implanted into the initial shell to create a “multicup” construct. The functional outcomes were evaluated in terms of the Harris Hip Score. Acetabular loosening, restoration of hip center of rotation, and bone ingrowth etc., were radiographically assessed. The survival rate of the implants was also evaluated.ResultsA followup lasting a mean time of 31 months (range, 18–57 months) revealed that the average Harris Hip Score improved from preoperative 37.0 ± 7.1 to postoperative 76.4 ± 9.0. There were no revisions due to acetabular loosening. The horizontal offset increased by an average of 14 mm, and the vertical offset decreased by an average of 18 mm. Eighteen of the 21 patients (86 %) met at least 3 of 5 criteria associated with bone ingrowth. The survivorship free from re-revision for acetabular loosening after 2 years was 100 %.ConclusionsThe multicup reconstruction technique was a simplified re-revision procedure for managing the severe protrusio acetabular defects and could achieve a high survival rate.Level of evidenceTherapeutic study, Level IVa.