Release Of Debris Research Articles

Plaque Echolucency May Play a Critical Role in Predicting Cerebral Embolization in Patients Undergoing Carotid Angioplasty and Stenting

Introduction Despite ongoing studies, the relationship of plaque echomorphology with increased risk of stroke in patients undergoing carotid angioplasty and stenting (CAS) remains elusive. The aim of this study is to examine whether carotid plaque echolucency is associated with greater plaque instability as determined by the quantification of captured embolic debris in CAS patients. Methods A total of 41 consecutive CAS patients with high-grade carotid stenosis were prospectively evaluated. B-mode images for 21 patients were available for analysis. Plaque echolucency was determined by grayscale median (GSM), a computer-assisted measure of echogenicity. Images were standardized with a GSM value of 0–5 for the vessel lumen and 185–195 for the adventitia. Echolucent (EL) plaques were defined by GSM < 25, and echogenic (EG) plaques were defined by GSM ≥ 25. Protective filters were visualized by stereomicroscopy along three perpendicular axes and quantified through video imaging software. Because of heterogeneity in particle shape, individual particle sizes were determined by greatest length. Results Mean GSM was 45.5, and 10% plaques were echolucent. Particulate debris was detected in all filters. Plaques with lower GSM were associated with a greater number of particles (EL: 33.5 ± 10.6 particles, EG: 14.0 ± 10.3 particles; p = 0.02). Echolucent plaques also demonstrated particles of greater size: maximum size (EL: 3490 ± 1954 μm, EG: 1026 ± 1186 μm; p = 0.015) and number of particles >1000 μm (EL: 3.5 ± 2.1 particles, EG: 0.7 ± 1.4 particles; p = 0.019). Conclusions Echolucent carotid plaques, as determined by GSM, may cause increased embolization of greater-sized embolic debris during CAS. Our study confirms previous findings that suggest that a GSM cut-off point of 25 may be linked with the release of more embolic debris. Therefore, increased plaque echolucency may place patients at greater risk for perioperative embolic events, making patients with such lesion characteristics more likely to experience postprocedural neurologic complications.

Modeling of the Drift and Accumulation of Tsunami-Driven Combustible Objects: Towards Tsunami-Induced Fire Spread Simulation

Fires that break out in tsunami inundation areas are collectively referred to as “tsunami-induced fires” in contrast with “seismic-induced fires” which have been conventionally a serious concern in Japan. Scenario of this new fire is basically as follows: (1) combustible objects such as houses are washed away by a tsunami, (2) combustible objects accumulate in tsunami inundation area as debris, (3) debris are ignited by some kind of cause, and (4) fires spread to adjacent debris resulting in conflagration in tsunami inundation area. We have been modeling tsunami-driven combustible objects as the first step towards development of tsunami-induced fire spread simulation. This modeling aims to know how combustible objects accumulate in tsunami inundation area to be the input data to fire models for ignition and fire spread. The proposed model is the extension of the existing model for driftwood by incorporating the debris release model and the effect of debris’s collision with surviving buildings. This model collaborates with the existing numerical simulation of tsunamis and is able to predict the drift and accumulation behavior of individual debris by solving the equation of horizontal translational motion. In this paper, we conducted debris diffusion simulation for Yamada, Iwate prefecture, Japan for model’s validation, where 16 ha of area were affected by tsunami-induced fire spread after the 2011 Great East Japan Earthquake Tsunami. The total number of debris tracked in the simulation was 1,850,560. A constant of proportionality, which determines the severity of force acting on drifting debris due to the collision with onshore surviving buildings, was identified by trial and error to maximize the eventual amount of accumulating debris within the fire-damaged zone. As a result, this maximum amount was predicted to be 4654 tons in the case that the constant is 0.1. Two thirds of the released debris, about 12,000 tons, accumulated onshore at the end of computation, and most of the fire-damaged zone was covered by these debris.

Improved Schmidt-hammer exposure ages for active and relict pronival ramparts in southern Norway, and their palaeoenvironmental implications

Eight pronival (protalus) ramparts from alpine southern Norway were dated using Schmidt-hammer exposure-age dating (SHD) based on local high-precision linear calibration equations. SHD ages were −1355±1240 to 815±1000years for three active ramparts and 8730±1050 to 14,635±1060years for five relict ramparts. Different parts of the same rampart yielded ages that were in generally good agreement. R-value frequency distributions enabled the identification single-age and mixed-age boulder populations, and the differentiation of active and relict rampart surfaces. The relict ramparts are located outside Younger Dryas glacier limits and probably formed over a period of ~6000years between deglaciation (following the Last Glacial Maximum of the late Weichselian, ~18,000years ago) and the end of the Younger Dryas (~11,700years ago). At that time, glacial debuttressing and permafrost degradation apparently enhanced the release of rock debris from rock faces to the ramparts. The active ramparts, which are located in areas deglaciated after the Younger Dryas, are relatively uncommon in the study area due to diminished paraglacial effects and limited debris supply associated with seasonally frozen ground during the Holocene. Thus, the legacy of glaciers, glacier–permafrost interaction, and the specific type of periglacial environment must all be considered when assessing the palaeoenvironmental and palaeoclimatic significance of pronival ramparts.

In situ electrochemical study of the interaction of cells with thermally treated titanium.

Micromotion and fretting wear between bone and Ti-based alloys in stem and dental implants breaks the passive film and exposes the metal to the action of the complex surrounding medium, generating substantial amounts of debris and continuous Ti ion release. In this work, oxidation treatments at low temperatures (277 °C, 5 h) have been used to promote the formation of wear-corrosion resistant titanium oxide on the Ti surface. The objective of this paper has been the study of the influence of live cells on the protectiveness of the oxide formed at these low temperatures. The interaction of cells with the modified surface has been studied by scanning electron microscopy, electrochemical impedance spectroscopy, polarization curves, and x-ray photoelectron spectroscopy (XPS). The chemical composition of the thermally treated Ti surface is mainly TiO2 as anatase-rich titanium dioxide with a low concentration of hydroxyl groups and a low mean nanoroughness that could promote good cell adhesion. The electrochemical results indicate that the cells alter the overall resistance of the thermally treated Ti surfaces by decreasing the oxide resistance with time. At the same time, the anodic current increases, which is associated with cathodic control, and is probably due to the difficulty of access of oxygen to the Ti substrate. XPS reveals the presence of proteins on the surface of the treated specimens in contact with the cells and a decrease in the Ti signal associated with the extracellular matrix on the surface and the reduction of the oxide thickness.

Mechanisms of incursion accommodation during interaction between a vibrating blade and an abradable coating

Abradable materials are used as inner coatings in aeronautical compressors. In the event of blade–casing interaction, the abradable coating accommodates the incursion of the blade tip in order to protect the blade and the casing from severe damage. In this study, an experiment was conducted in conditions representative of the full-scale situation in terms of velocity, temperature and the dynamical characteristics of blades. The mechanisms of incursion accommodation were investigated based on dynamical data and a post mortem analysis of the coating and the wear debris. First, dynamical blade tip incursion was estimated by considering blade vibrations and coating waviness. The tip incursion was found to be significantly different from the measured displacement of the blade foot. Next, a post mortem analysis of the coating was performed at the surface and sub-surface. Four mechanisms were identified, namely debris release, surface shearing, compaction and reversible deformation. Care was taken to provide orders of magnitude for the different mechanisms relating to residual thickness loss of the coating.

Rock‐protecting seaweed? Experimental evidence of bioprotection in the intertidal zone

AbstractBiogeomorphological processes are an important component of dynamic intertidal systems. On rocky shores, the direct contribution of microorganisms, plants and animals to weathering and erosion is well known. There is also increasing evidence that organisms can alter rock breakdown indirectly, by moderating temperature and moisture regimes at the rock–air interface. These influences have been purported to represent mechanisms of bioprotection, by buffering microclimatic fluctuations associated with weathering processes such as wetting and drying and salt crystallization. However, virtually nothing has been done to test whether microclimatic buffering translates to differences in actual rock breakdown rates.Here we report a preliminary laboratory experiment to assess how an artificial canopy (chosen to represent seaweed) affects mechanical rock breakdown. Using a simplified and accelerated thermal regime based on field data from a rocky shore platform in southern England, UK, we find that breakdown (mineral debris release) of mudstone covered with a canopy is reduced by as much as 79% relative to bare rock after around 100 thermal cycles. Reduction in rock surface hardness (measured using an Equotip device) was also greater for bare rock (17%) compared to covered rock (10%) over this period. Measurements of salt crystal formation indicate that the mechanism driving these differences was a reduction in the frequency of crystallization events, via moisture retention and shading of the rock surface. Copyright © 2015 John Wiley & Sons, Ltd.

Nano-scale wear characterization of CoCrMo biomedical alloys

Low amplitude motions at the micro and the nano-scale at the femoral stem–cement interface under physiological loads can result in fretting and nano-wear on the stem surface. These are important wear processes in cemented total hip replacements as the release of metal debris and ions can trigger adverse local tissue reactions within the body, bone resorption and subsequent aseptic loosening of the femoral component resulting in the implant failure. However, the influence of the microstructure and manufacturing processes on the nano-wear behaviour of different cobalt chromium molybdenum (CoCrMo) alloys has not been studied extensively. Four CoCrMo alloys were tested under reciprocating wear conditions at the nano-scale level. Tangential friction forces, coefficient of friction and plastic deformation values were recorded. A new white-light-interferometer system was validated against atomic force microscopy and Nano Vantage Test System measurements to analyse the permanent plastic deformation caused in each of the samples. Significant differences were found in the total plastic deformation achieved by the as cast alloy compared to the forged, as cast single thermal treated and as cast double thermal treated samples. In addition thermal treated samples presented a tendency to produce a higher quantity of wear debris around the nano-wear scars. These findings indicate a possible relation between the wear resistance at the nano-scale and the manufacturing and thermal processes applied on the CoCrMo biomedical alloys.

Metal ions as inflammatory initiators of osteolysis.

Osteolysis and aseptic loosening currently contribute 75 % of implant failures. Furthermore, with over four million joint replacements projected to be performed in the United States annually, osteolysis and aseptic loosening may continue to pose a significant morbidity. This paper reviews the osteolysis cascade leading to osteoclast activation and bone resorption at the biochemical level. Additionally, the metal ion release mechanism from metallic implants is elucidated. Even though metal ions are not the predominating initiator of osteolysis, they do increase the concentration of key inflammatory cytokines that stimulate osteoclasts and prove to be a contributor to osteolysis and aseptic loosening. Osteolysis is a competitive mechanism among a number of biological reactions, which includes debris release, macrophage and osteoclast activation, an inflammatory response as well as metal ion release. Pharmacological therapy for component loosening has also been reviewed. A non-surgical treatment of osteolysis has not been found in the literature and thus may become an area of future research. Even though this research is warranted, comprehensively understanding the immune response to orthopedic implants and their metallic ions, and thus, creating improved prostheses appears to be the most cost-effective approach to decrease the morbidity related to osteolysis and to design implants with greater longevity. The ionic forms, cytokines, toxicity, gene expression, biological effects, and hypersensitivity responses of metallic elements from metal implants are summarized as well.

Plaque Echolucency May Play a Critical Role in Predicting Cerebral Embolization in Patients Undergoing Carotid Angioplasty and Stenting

Introduction Despite ongoing studies, the relationship of plaque echomorphology with increased risk of stroke in patients undergoing carotid angioplasty and stenting (CAS) remains elusive. The aim of this study is to examine whether carotid plaque echolucency is associated with greater plaque instability as determined by the quantification of captured embolic debris in CAS patients. Methods A total of 41 consecutive CAS patients with high-grade carotid stenosis were prospectively evaluated. B-mode images for 21 patients were available for analysis. Plaque echolucency was determined by grayscale median (GSM), a computer-assisted measure of echogenicity. Images were standardized with a GSM value of 0–5 for the vessel lumen and 185–195 for the adventitia. Echolucent (EL) plaques were defined by GSM < 25, and echogenic (EG) plaques were defined by GSM ≥ 25. Protective filters were visualized by stereomicroscopy along three perpendicular axes and quantified through video imaging software. Because of heterogeneity in particle shape, individual particle sizes were determined by greatest length. Results Mean GSM was 45.5, and 10% plaques were echolucent. Particulate debris was detected in all filters. Plaques with lower GSM were associated with a greater number of particles (EL: 33.5 ± 10.6 particles, EG: 14.0 ± 10.3 particles; p = 0.02). Echolucent plaques also demonstrated particles of greater size: maximum size (EL: 3490 ± 1954 μm, EG: 1026 ± 1186 μm; p = 0.015) and number of particles >1000 μm (EL: 3.5 ± 2.1 particles, EG: 0.7 ± 1.4 particles; p = 0.019). Conclusions Echolucent carotid plaques, as determined by GSM, may cause increased embolization of greater-sized embolic debris during CAS. Our study confirms previous findings that suggest that a GSM cut-off point of 25 may be linked with the release of more embolic debris. Therefore, increased plaque echolucency may place patients at greater risk for perioperative embolic events, making patients with such lesion characteristics more likely to experience postprocedural neurologic complications.

Space debris removal by ground-based lasers: main conclusions of the European project CLEANSPACE.

Studies show that the number of debris in low Earth orbit is exponentially growing despite future debris release mitigation measures considered. Specifically, the already existing population of small and medium debris (between 1cm and several dozens of cm) is today a concrete threat to operational satellites. A ground-based laser solution which can remove, at low expense and in a nondestructive way, hazardous debris around selected space assets appears as a highly promising answer. This solution is studied within the framework of the CLEANSPACE project which is part of the FP7 space program. The overall CLEANSPACE objective is: to propose an efficient and affordable global system architecture, to tackle safety regulation aspects, political implications and future collaborations, to develop affordable technological bricks, and to establish a roadmap for the development and the future implantation of a fully functional laser protection system. This paper will present the main conclusions of the CLEANSPACE project.

A Comparative Hip Joint Simulator Study of the Wear, Debris and Metal Ion Release of CoCrMo / CoCrMo and CoCrMo / CL-UHMWPE Couplings

A Comparative Hip Joint Simulator Study of the Wear, Debris and Metal Ion Release of CoCrMo / CoCrMo and CoCrMo / CL-UHMWPE Couplings

Treating orthopedic prosthesis with diamond-like carbon: minimizing debris in Ti6Al4V.

Prostheses are subject to various forms of failing mechanisms, including wear from ordinary patient motion. Superficial treatments can improve tribological properties of the contact pair, minimizing wear and increasing prostheses lifetime. One possibility is the diamond-like carbon (DLC) coating, where Carbon is deposited with variable ratio of sp(2)/sp(3) structures, leading to an increase in surface hardness. So in this research Ti6Al4V samples were coated with DLC using sputtering process to evaluate the debris release. The Ti6Al4V and Ti6Al4V plus DLC coating surfaces were analyzed using Raman spectroscopy and instrumented indentation (hardness). The wear behavior was tested using a reciprocating linear tribometer. The wear rate was smaller in the coated samples, producing less debris than the untreated Ti6Al4V alloy. Debris morphology was also evaluated, using scanning electronic microscopy, and it was observed that debris size from the coated samples were bigger than those observed from the uncoated Ti6Al4V alloy, above the size that generally triggers biological response from the host.

Stochastic Simulation of Modular Connections in Total Hip Replacement

Several modern Total Hip Arthroplasty (THA) implants have been associated with increased release of metallic debris through combined mechanical fretting wear and chemical corrosion. These particles can lead to painful Adverse Reaction to Metallic Debris, often requiring early revision [1]. While much research has focused on improving the performance of bearing surfaces, the key parameters driving release of metallic debris at modular junctions remains unclear.© 2013 ASME

Applying diamond like carbon layer on carbon/carbon composites and its effect on the deposition of hydroxyapatite coating

The biomedical application of carbon/carbon (C/C) composites is limited by lacking bioactivity and releasing carbon debris. Hydroxyapatite (HA) coating has been used to improve the bioactivity of C/C composites, but it cannot reduce the release of carbon debris effectively because of poor wear resistance property. In this work, a wear‐resistant layer of diamond like carbon (DLC) is applied on C/C composites, followed by an ultrasound‐assisted electrochemical deposition to prepare HA coatings. The microstructure, morphology and chemical composition of the DLC layer and the HA coating are characterised by scanning electron microscopy, X‐ray diffraction, energy dispersive spectroscopy (EDS), X‐ray photoelectron spectroscopy, Fourier transformed infrared spectroscopy and Raman spectrum. The bonding strength between the HA coating and the DLC layer modified C/C composites is examined by a tensile test. The results show that the DLC layer has a spherical morphology and provides a uniform surface for the deposition of the HA coating. The HA coating shows flaky morphology with a compact structure. The tensile strength of the HA coating on the DLC layer modified C/C composites is 6.24 ± 0.40 MPa, which is significantly higher than that of HA coating on unmodified C/C composites(3.04 ± 0.20 MPa). Copyright © 2013 John Wiley & Sons, Ltd.

Antiphospholipid antibodies internalised by human syncytiotrophoblast cause aberrant cell death and the release of necrotic trophoblast debris

Antiphospholipid antibodies (aPL) are the strongest maternal risk factor for pre-eclampsia, a hypertensive disease of human pregnancy. Pre-eclampsia is triggered by a toxic factor released from the placenta that activates the maternal endothelium. Antiphospholipid antibodies cause the release of necrotic trophoblast debris from the placental syncytiotrophoblast and this debris can activate endothelial cells. In this study, we investigated how aPL affects syncytiotrophoblast death and production of necrotic trophoblast debris by examining the interaction between aPL and human first trimester placental explants. Human polyclonal and murine monoclonal aPL, but not control antibodies, were rapidly internalised by the syncytiotrophoblast. Inhibitors of endocytosis or the low-density lipoprotein receptor (LDLR) family, but not toll-like receptors, decreased the internalisation of aPL and prevented the release of necrotic trophoblast debris from the syncytiotrophoblast. Once internalised, aPL increased inner mitochondrial membrane leak and Cytochrome c release while depressing oxidative flux through Complex IV of the electron transport system in syncytiotrophoblast mitochondria. These data suggest that the human syncytiotrophoblast internalises aPL by antigen-dependent endocytosis involving LDLR family members. Once internalised by the syncytiotrophoblast, aPL affects the death-regulating mitochondria, causing extrusion of necrotic trophoblast debris which can activate maternal endothelial cells thereby contributing to the pathogenesis of pre-eclampsia.

Magnetresonanztomographische Untersuchungen bei Problemen mit Metall-auf-Metall-Implantaten

Until recently, metal-on-metal (MoM) hip implants were commonly used for joint replacement and resurfacings. Their use has rapidly declined following reports of Frühversagen and soft tissue disease caused by the release of metal debris from the prosthesis. Detection of these soft tissue lesions has proven difficult using conventional imaging techniques and blood metal ion tests. Current guidelines recommend the use of imaging modalities including metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI), computed tomography and ultrasound but provide little indication which is best. MARS significantly reduces the susceptibility artefact induced by the presence of metal objects, thereby producing diagnostic quality images that can be shared with other physicians and compared over time. The clinical interpretation of MRI findings of solid pseudotumours and severe muscle atrophy is straightforward: revision is usually recommended. However, the most common MRI findings are of a cystic pseudotumour and minor muscle wasting. In these cases decision-making is difficult and we currently use multi-disciplinary and multi-colleague based meetings to make decisions regarding patient management. This article presents a comparison of imaging modalities and an update on the interpretation of MARS MRI for the investigation of patients with MoM hip implants.The English full-text version of this article is available at Springer Link (under "Supplemental").

Landscape of Transcriptional Deregulations in the Preeclamptic Placenta

Preeclampsia is a pregnancy disease affecting 5 to 8% of pregnant women and a leading cause of both maternal and fetal mortality and morbidity. Because of a default in the process of implantation, the placenta of preeclamptic women undergoes insufficient vascularization. This results in placental ischemia, inflammation and subsequent release of placental debris and vasoactive factors in the maternal circulation causing a systemic endothelial activation. Several microarray studies have analyzed the transcriptome of the preeclamptic placentas to identify genes which could be involved in placental dysfunction. In this study, we compared the data from publicly available microarray analyses to obtain a consensus list of modified genes. This allowed to identify consistently modified genes in the preeclamptic placenta. Of these, 67 were up-regulated and 31 down-regulated. Assuming that changes in the transcription level of co-expressed genes may result from the coordinated action of a limited number of transcription factors, we looked for over-represented putative transcription factor binding sites in the promoters of these genes. Indeed, we found that the promoters of up-regulated genes are enriched in putative binding sites for NFkB, CREB, ANRT, REEB1, SP1, and AP-2. In the promoters of down-regulated genes, the most prevalent putative binding sites are those of MZF-1, NFYA, E2F1 and MEF2A. These transcriptions factors are known to regulate specific biological pathways such as cell responses to inflammation, hypoxia, DNA damage and proliferation. We discuss here the molecular mechanisms of action of these transcription factors and how they can be related to the placental dysfunction in the context of preeclampsia.

Tannic acid-dependent modulation of selected Lactobacillus plantarum traits linked to gastrointestinal survival.

BackgroundOwing to its antimicrobial properties dietary tannins may alter the functional efficacy of probiotic lactobacilli in the gastrointestinal (GI)-tract influencing their growth, viability and molecular adaptation to the intestinal environment.Methods and FindingsThe effects of tannic acid on Lactobacillus plantarum WCFS1 were studied by in vitro growth monitoring and visualizing the morphological alteration on the cell wall using transmission electron microscopy. Growth upon tannic acid was characterized by dose-dependent reductions of initial viable counts and extended lag phases. Lag phase-cells growing upon 0.5 mM tannic acid were abnormally shaped and experienced disturbance on the cell wall such as roughness, occasional leakage and release of cell debris, but resumed growth later at tannic acid concentrations high as 2.5 mM. To gain insight on how the response to tannic acid influenced the molecular adaptation of L. plantarum to the GI-tract conditions, gene expression of selected biomarkers for GI-survival was assessed by RT-qPCR on cDNA templates synthetized from mRNA samples obtained from cells treated with 0.5 or 2 mM tannic acid. Tannic acid-dependent gene induction was confirmed for selected genes highly expressed in the gut or with confirmed roles in GI-survival. No differential expression was observed for the pbp2A gene, a biomarker negatively related with GI-survival. However PBP2A was not labeled by Bocillin FL, a fluorescent dye-labeled penicillin V derivative, in the presence of tannic acid which suggests for enhanced GI-survival reportedly associated with the inactivation of this function.ConclusionsProbiotic L. plantarum WCFS1 is able to overcome the toxic effects of tannic acid. This dietary constituent modulates molecular traits linked to the adaptation to intestinal environment in ways previously shown to enhance GI-survival.

Cobalt triggers necrotic cell death and atrophy in skeletal C2C12 myotubes

Severe poisoning has recently been diagnosed in humans having hip implants composed of cobalt–chrome alloys due to the release of particulate wear debris on polyethylene and ceramic implants which stimulates macrophagic infiltration and destroys bone and soft tissue, leading to neurological, sensorial and muscular impairments. Consistent with this premise, in this study, we focused on the mechanisms underlying the toxicity of Co(II) ions on skeletal muscle using mouse skeletal C2C12 myotubes as an in vitro model. As detected using propidium iodide incorporation, increasing CoCl2 doses (from 5 to 200μM) affected the viability of C2C12 myotubes, mainly by cell necrosis, which was attenuated by necrostatin-1, an inhibitor of the necroptotic branch of the death domain receptor signaling pathway. On the other hand, apoptosis was hardly detectable as supported by the lack of caspase-3 and -8 activation, the latter resulting in only faint activation after exposure to higher CoCl2 doses for prolonged time points. Furthermore, CoCl2 treatment resulted in atrophy of the C2C12 myotubes which was characterized by the increased expression of HSP25 and GRP94 stress proteins and other typical `pro-atrophic molecular hallmarks, such as early activation of the NF-kB pathway and down-regulation of AKT phosphorylation, followed by the activation of the proteasome and autophagy systems. Overall, these results suggested that cobalt may impact skeletal muscle homeostasis as an inducer of cell necrosis and myofiber atrophy.

Adverse Local Tissue Reaction Arising from Corrosion at the Femoral Neck-Body Junction in a Dual-Taper Stem with a Cobalt-Chromium Modular Neck

Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction. This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction. The cohort included eight women and three men who together had an average age of 60.1 years (range, forty-three to seventy-seven years); all hips were implanted with a titanium-alloy stem and cobalt-chromium-alloy neck. Patients presented with new-onset and increasing pain at a mean of 7.9 months (range, five to thirteen months) following total hip arthroplasty. After serum metal-ion studies and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) revealed abnormal results, the patients underwent hip revision at a mean of 15.2 months (range, ten to twenty-three months). Tissue specimens were examined by a single histopathologist, and the retrieved implants were studied with use of light and scanning electron microscopy. Serum metal levels demonstrated greater elevation of cobalt (mean, 6.0 ng/mL) than chromium (mean, 0.6 ng/mL) or titanium (mean, 3.4 ng/mL). MRI with use of MARS demonstrated adverse tissue reactions in eight of nine patients in which it was performed. All hips showed large soft-tissue masses and surrounding tissue damage with visible corrosion at the modular femoral neck-body junction. Available histology demonstrated large areas of tissue necrosis in seven of ten cases, while remaining viable capsular tissue showed a dense lymphocytic infiltrate. Microscopic analysis was consistent with fretting and crevice corrosion at the modular neck-body interface. Corrosion at the modular neck-body junction in dual-tapered stems with a modular cobalt-chromium-alloy femoral neck can lead to release of metal ions and debris resulting in local soft-tissue destruction. Adverse local tissue reaction should be considered as a potential cause for new-onset pain in patients with these components, and early revision should be considered given the potentially destructive nature of these reactions. A workup including serologic studies (erythrocyte sedimentation rate and C-reactive protein), serum metal levels, and MARS MRI can be helpful in establishing this diagnosis.