Confirmation of Safety of Titanium Wire in Sternotomy Closure, A Randomized Prospective Study.

BACKGROUND: There are many factors that are known to increase the risk of sternal wound infection (SWI); some studies have reported that nickel is a risk factor for SWI. Titanium wires have only been used as an alternative to steel wires in patients with known allergy to nickel. However, there is a paucity of literature regarding the safety of using titanium wires compared to that on the safety of steel wires for sternum closure after cardiac surgery. Therefore, this study aimed to demonstrate the noninferiority of titanium wires, even in patients without a known allergy. METHODS: A total of 322 patients who underwent elective full median sternotomy were randomly assigned to sternal closure either by titanium wires (n = 161) or by stainless steel wires. RESULTS: Fourteen patients had sternal instability, six (3.7%) patients in the titanium group and eight (5%) patients in the stainless steel group (p = 0.585). There was no statistically significant difference between both groups in terms of postoperative wound infection (p = 0.147). Patients in the titanium group experienced statistically significant lower postoperative pain than those in the stainless steel group (p = 0.024). The wire type was not an independent risk factor for SI, as shown by univariate and logistic regression analyses. CONCLUSION: Titanium wires are a good alternative and have been proven to be safe and effective for sternal closure. The surgeon should be aware of the possibility of developing an allergic reaction to the wires, especially in patients with previous multiple allergic histories.

Artificial shear stress effects on leukocytes at a biomaterial interface.

Medical devices, such as ventricular assist devices (VADs), introduce both foreign materials and artificial shear stress to the circulatory system. The effects these have on leukocytes and the immune response are not well understood. Understanding how these two elements combine to affect leukocytes may reveal why some patients are susceptible to recurrent device-related infections and provide insight into the development of pump thrombosis. Biomaterials-DLC: diamond-like carbon-coated stainless steel; Sap: single-crystal sapphire; and Ti: titanium alloy (Ti6 Al4 V) were attached to the parallel plates of a rheometer. Whole human blood was left between the two discs for 5 minutes at +37°C with or without the application of shear stress (0 s-1 or 1000 s-1 ). Blood was removed and used for complete blood cell counts, flow cytometry (leukocyte activation, cell death, microparticle generation, phagocytic ability, and reactive oxygen species [ROS] production), and the production of pro-inflammatory cytokines. L-selectin expression on monocytes was decreased when blood was exposed to the biomaterials both with and without shear. Applying shear stress to blood on a Sap and Ti surface led to activation of neutrophils shown as decreased L-selectin expression. Sap and Ti blunted the LPS-stimulated macrophage migration inhibitory factor (MIF) production, most notably when sheared on Ti. The biomaterials used here have been shown to activate leukocytes in a static environment. The introduction of shear appears to exacerbate this activation. Interestingly, a widely accepted biocompatible material (Ti) utilized in many different types of devices has the capacity for immune cell activation and inhibition of MIF secretion when combined with shear stress. These findings contribute to our understanding of the contribution of biomaterials and shear stress to recurrent infections and vulnerability to sepsis in some VAD patients as well as pump thrombosis.

Biological safety of Electroacupuncture with STS316 needles.

BACKGROUND: Electroacupuncture (EA) is often used in clinical settings due to its analgesic effect, but its safety has not been verified due to the lack of clear criteria. This study examined the critical range of the corrosion of stainless steel types STS304 and STS316, which have been used clinically, and the relationship between needle corrosion and cell necrosis. METHOD: The critical point of corrosion for STS304 and STS316 was identified by varying the time, frequency, and stimulation intensity. In a tissue necrosis experiment, EA stimulation was applied to rats using STS316 needles with different thicknesses at maximum intensity for 60 min, and the presence of corrosion and tissue necrosis was determined. A cytotoxicity experiment was also conducted and assessed the needles and tissue necrosis. RESULTS: The results showed that STS316 was more stable than STS304 and that only coated needles corroded. Furthermore, tissue necrosis was observed regardless of corrosion, and slight cell necrosis was associated with needles with corrosion. CONCLUSIONS: This study demonstrated that non-coated STS316 was the most stable for EA stimulation and that corrosion byproducts and cell necrosis were not directly related.

Locking screw-plate interface stability in carbon-fibre reinforced polyetheretherketone proximal humerus plates.

PURPOSE: Carbon-fibre reinforced polyetheretherketone (CFR-PEEK) plates have recently been introduced for proximal humerus fracture treatment. The purpose of this study was to compare the locking screw-plate interface stability in CFR-PEEK versus stainless steel (SS) proximal humerus plates. METHODS: Locking screw mechanical stability was evaluated independently in proximal and shaft plate holes. Stiffness and load to failure were tested for three conditions: (1) on-axis locking screw insertion in CFR-PEEK versus SS plates, (2) on-axis locking screw insertion, removal, and reinsertion in CFR-PEEK plates, and (3) 10-degree off-axis locking screw insertion in CFR-PEEK plates. Cantilever bending at a rate of 1 mm/minute was produced by an Instron machine and load-displacement data recorded. RESULTS: Shaft locking screw load to failure was significantly greater in CFR-PEEK plates compared to SS plates (746.4 ± 89.7 N versus 596.5 ± 32.6 N, p < 0.001). The stiffness and load to failure of shaft locking screws was significantly decreased when inserted 10 degrees off-axis compared to on-axis in CFR-PEEK plates (p < 0.001). Stiffness and load to failure did not vary significantly following screw reinsertion in CFR-PEEK plates. CONCLUSION: The mechanical stability of locking screws in CFR-PEEK plates is comparable or superior to locking screws in SS plates.

Ion Release and Galvanic Corrosion of Different Orthodontic Brackets and Wires in Artificial Saliva.

INTRODUCTION: To investigate the galvanic corrosion of brackets manufactured by four different companies coupled with stainless steel (SS) or nickel-titanium (NiTi) wires in an artificial saliva solution. MATERIALS AND METHODS: A total of 24 mandibular central incisor Roth brackets of four different manufacturers (American Orthodontics, Dentaurum, Shinye, ORJ) were used in this experimental study. These brackets were immersed in artificial saliva along with SS or NiTi orthodontic wires (0.016'', round) for 28 days. The electric potential difference of each bracket/ wire coupled with a saturated calomel reference electrode was measured via a voltmeter and recorded constantly. Corrosion rate (CR) was calculated, and release of ions was measured with an atomic absorption spectrometer. Stereomicroscope was used to evaluate all samples. Then, samples with corrosion were further assessed by scanning electron microscope and energy-dispersive X-ray spectroscopy. Two-way analysis of variance was used to analyze data. RESULTS: Among ions evaluated, release of nickel ions from Shinye brackets was significantly higher than that of other brackets. The mean potential difference was significantly lower in specimens containing a couple of Shinye brackets and SS wire compared with other specimens. No significant difference was observed in the mean CR of various groups (p > 0.05). Microscopic evaluation showed corrosion in two samples only: Shinye bracket coupled with SS wire and American Orthodontics bracket coupled with NiTi wire. CONCLUSION: Shinye brackets coupled with SS wire showed more susceptibility to galvanic corrosion. There were no significant differences among specimens in terms of the CR or released ions except the release of Ni ions, which was higher in Shinye brackets.

Effect on Clinical Restenosis of an Ultra-Thin-Strut Bare Metal Cobalt-Chromium Stent Versus a Thin-Strut Stainless Steel Stent.

OBJECTIVES: To prospectively compare the impact of ultrathin-strut cobalt-chromium (Cro-Co) bare metal stent (BMS) versus thin-strut stainless steel (SS) BMS on clinically driven target lesion revascularization (TLR). BACKGROUND: Stent characteristics are an important determinant of restenosis. Thinner strut Cro-Co BMS is associated with a reduction of neointimal formation compared to SS BMS. The advantages of Cro-Co BMS in a real-world population is not clear. METHODS: Patients undergoing percutaneous coronary intervention (PCI) with BMS for any reason were enrolled. Patient with multi-vessel PCI, multi-lesions PCI, PCI of unprotected left main and coronary grafts were not excluded. They were divided in two groups according to stent type: Cro-Co or SS group. The primary endpoint was clinically driven TLR at follow-up. RESULTS: A total of 383 patients were enrolled: 222 in SS and 161 in Cro-Co group. During the follow-up, Cro-Co patients had a significantly lower occurrence of TLR compared to SS patients (1.9% vs 8.6%, P = 0.006). There were no significant differences for the composite endpoint of death, myocardial infarct, and stroke (4.9% in Cro-Co group vs 9.5% in SS group, P = 0.119). At multivariate analysis, the variables that were predictors of TLR were: use of SS stent (OR 4.43, P = 0.019) and diabetes (OR 2.84, P = 0.025). CONCLUSIONS: Ultra-thin strut Cro-Co BMS is associated with a significant reduction of clinically driven TLR in all comers population with any type of coronary disease complexity. (J Interven Cardiol 2016;29:300-310).

Spinal metallosis: a systematic review.

PURPOSE: To document a rarely reported complication associated with spinal instrumentation and to evaluate the current literature on spinal metallosis and spinal metalloma. METHODS: A local case report is presented. EBSCOhost, PubMed and ScienceDirect databases were used to conduct a systematic review for articles describing spinal metallosis and spinal metalloma. RESULTS: A total of 836 articles were identified using the terms "metalloma" or "metallosis". Exclusion of arthroplasty-related abstracts retrieved 46 articles of which 3 full text articles presenting spinal metalloma as a causative pathological finding responsible for neurological signs and symptoms in patients with previous spinal fusion instrumentation were reviewed. Our case is the first described with titanium-composed posterior instrumentation and fifth reported, demonstrating the phenomena of neurological symptoms and signs attributed directly to neural tissue compression by spinal metalloma after spinal instrumentation. CONCLUSION: Spinal metallosis can present weeks to years after spinal instrumentation surgery and is a potential cause of neural compression. This process appears to be independent of the instrument composition as metallosis has now been demonstrated in both titanium and stainless steel constructs.

Cause-specific mortality in Finnish ferrochromium and stainless steel production workers.

BACKGROUND: Although stainless steel has been produced for more than a hundred years, exposure-related mortality data for production workers are limited. AIMS: To describe cause-specific mortality in Finnish ferrochromium and stainless steel workers. METHODS: We studied Finnish stainless steel production chain workers employed between 1967 and 2004, from chromite mining to cold rolling of stainless steel, divided into sub-cohorts by production units with specific exposure patterns. We obtained causes of death for the years 1971-2012 from Statistics Finland. We calculated standardized mortality ratios (SMRs) as ratios of observed and expected numbers of deaths based on population mortality rates of the same region. RESULTS: Among 8088 workers studied, overall mortality was significantly decreased (SMR 0.77; 95% confidence interval [CI] 0.70-0.84), largely due to low mortality from diseases of the circulatory system (SMR 0.71; 95% CI 0.61-0.81). In chromite mine, stainless steel melting shop and metallurgical laboratory workers, the SMR for circulatory disease was below 0.4 (SMR 0.33; 95% CI 0.07-0.95, SMR 0.22; 95% CI 0.05-0.65 and SMR 0.16; 95% CI 0.00-0.90, respectively). Mortality from accidents (SMR 0.84; 95% CI 0.67-1.04) and suicides (SMR 0.72; 95% CI 0.56-0.91) was also lower than in the reference population. CONCLUSIONS: Working in the Finnish ferrochromium and stainless steel industry appears not to be associated with increased mortality.

Allergic reaction to stainless steel sternotomy wires requiring removal: A case report and literature review.

Hypersensitivity to stainless steel sternal sutures are an uncommon occurrence. We present a case of such a patient who developed chronic tissue overgranulation over a sternotomy wound eight weeks post-operatively. Primary suspicion was infection, a more common complication however radiological and laboratory investigation showed otherwise. Conservative management provided limited ephemeral success. After ensuring adequate sternal bone healing, the sutures and granulation tissue were eventually surgically removed without complication and the reoperated wound healed well.

Adverse effects of nickel in transosseous wires and surgical implants: literature review.

INTRODUCTION: Transosseous wires used in the management of fractures are stainless steel alloys which contain nickel 14.5%, chromium 17.6%, iron 62.5% and molybdenum 2.8%. Gradual disintegration of the transosseous wires release nickel into the blood leading to increase nickel concentration in the blood. Nickel has been found to have some adverse systemic effects on the body. The aim of this paper is to discuss the sources of Nickel in the body as well as the systemic adverse effects of Nickel as a degradation product of stainless steel surgical implants. METHODS: A study of pertinent literature on nickel as a content of stainless steel alloy used in implant surgery was done, taking note also of other sources of nickel in the body, the toxicokinetics of nickel and the related adverse effects of this metal and its compound in humans. RESULTS: As outcome,the sources of human exposure to nickel,distribution and metabolism of nickel in the body, host responseto stainless steel wires and the adverse effects of nickel in the body are presented. CONCLUSION: It may be necessary to discourage the use of wires or implants containing nickel in the management of fractures.The need for removal of these implants after they have served their purposes is emphasized.

Isolated fracture of the hip stem prosthesis made of austenitic steel - a literature review.

Proper design and functioning of the hip joint ensure smooth motion over the full range in multiple planes. Any change in this arrangement may lead to joint damage, causing deformation, pain and loss of functionality. Hip replacement is a procedure intended to replace the damaged articular surfaces and replacing them with artificial components. However, as any surgical intervention, it carries the risk of serious complications. One of them are isolated stem fractures, consisting of breaking the implant inside the intramedullary canal without damaging the surrounding tissue. This article contains a review of the literature data concerning the clinical cases of isolated fractures of hip endoprosthesis stems made of austenitic stainless steel. Although stem fractures are one of the rarest complications of implantation, the lack of clear description of the causes of this phenomenon in the literature makes it worthwhile to take up on the subject.

A delayed hypersensitivity reaction to a stainless steel crown: a case report.

Stainless steel crowns are commonly used to restore primary or permanent teeth in pediatric restorative dentistry. Here, we describe a case of a delayed hypersensitivity reaction, which manifested itself as perioral skin eruptions, after restoring the decayed first permanent molar tooth of a 13-year-old Caucasian girl with a preformed stainless steel crown. The eruptions completely healed within one week after removal of the stainless steel crown. The decayed tooth was then restored with a bis-acryl crown and bridge. Since no perioral skin eruptions occurred during the six-month follow-up, we presume that the cause of the perioral skin eruptions was a delayed hypersensitivity reaction, which was triggered by the nickel in the stainless steel crown.

Dermatitis in patients undergoing the Nuss procedure for correction of pectus excavatum.

BACKGROUND: The Nuss procedure was introduced in 1987 for the correction of pectus excavatum. In this procedure, a stainless steel bar is placed underneath the sternum. OBJECTIVES: To report cutaneous reactions associated with Nuss bar placement. METHODS: Over a period of 30 months, 50 patients underwent the Nuss procedure. The study population was limited to those who developed clinically significant cutaneous reactions postoperatively. Patient information was obtained from electronic medical records. All patients had been patch tested preoperatively with stainless steel discs supplied by the bar manufacturer. When performed, expanded patch testing was carried out in accordance with the North American Contact Dermatitis Group guidelines. RESULTS: Postoperatively, 3 patients developed areas of protuberant granulation tissue at one or more incision sites. One patient developed localized oedema, dermatitis, and lymphadenopathy. Two of these 4 patients underwent further patch testing. Of these 2, 1 with dermatitis had a positive reaction to nickel and the other, with granulation tissue, tested negative for metal allergy. CONCLUSIONS: Despite clinical evidence of cutaneous reactions or putative allergy, no patient required early removal of the bar(s). Cutaneous testing with stainless steel discs supplied by the bar manufacturer does not provide accurate screening for allergy to the implant used in the Nuss procedure.

Comparative Analysis of NF-κB in the MyD88-Mediated Pathway After Implantation of Titanium Alloy and Stainless Steel and the Role of Regulatory T Cells.

OBJECTIVE: Development of immunologically smart implants, integrated to biological systems, is a key aim to minimize the inflammatory response of the host to biomaterial implants. METHODS: The aim of this study is to investigate the influence of titanium alloy and stainless steel implants on immunological responses in rats by comparative analysis of nuclear factor kappa B (NF-κB) profiles in the activation of inflammatory signaling pathways and the role of CD4+CD25+Foxp3+. RESULTS: Both Ti alloy and stainless steel alloy group implantation affect Toll-like receptors-4 pathways and CD4+CD25+ regulatory T cells in different ways. CONCLUSIONS: Results show that NF-κB/p65 and NF-κB1/p50 possess potential as a therapeutic target in the prevention of adverse reactions to metal, especially for controlling inflammation after the implantation.

Lack of toxicity of stainless steel retinal tacks during 21 years of follow-up.

Retinal tacks were historically used in the repair of complex retinal detachment associated with giant retinal tear. The authors describe a patient with retinal detachment associated with giant retinal tear who was treated successfully with pars plana vitrectomy, use of stainless steel retinal tacks, endolaser photocoagulation, and gas-fluid exchange. Twenty-one years after treatment, the retina has remained attached, the tacks are in place, and best-corrected visual acuity is 20/30 in the operated eye. Although retinal tacks are no longer used, this case report suggests that intraocular stainless steel may cause minimal or no retinal toxicity during long-term follow-up.

A correlation found between contact allergy to stent material and restenosis of the coronary arteries.

BACKGROUND: Metallic implants, stents, are increasingly being used especially in patients with stenosis of the cardiac vessels. Ten to thirty per cent of the patients suffer from restenosis regardless of aetiology. We have shown increased frequency of contact allergy to stent metals in stented patients. OBJECTIVES: To we evaluate whether contact allergy to stent material is a risk factor for restenosis. METHODS: Patients with stainless steel stents, with or without gold plating, were epicutaneously tested and answered a questionnaire. The restenosis rate was evaluated. RESULTS: We found a correlation between contact allergy to gold, gold stent, and restenosis (OR 2.3, CI 1.0-5.1, P = 0.04). The risk for restenosis was threefold increased when the patient was gold allergic and stented with a gold-plated stent. An increased degree of chest pain in gold-allergic patients stented with gold-plated stent was found. CONCLUSIONS: We found a correlation between contact allergy to gold, gold-stent, and restenosis. It may be of importance to consider contact allergy when developing new materials for stenting.

Face and neck dermatitis from a stainless steel orthodontic appliance.

Although nickel is the most common cause of contact allergy, nickel-containing orthodontic appliances seldom cause adverse reactions that result in discontinuation of treatment. We report on an eruption of dermatitis in the face and neck of an adult female patient after placement of a rapid maxillary expansion appliance (RME). Because the patient suspected nickel allergy, her tolerance to the appliance material was tested intraorally before treatment by cementing bands on four teeth for a week. No visible adverse reactions were seen during the test. One week after cementation of the RME appliance, the patient reported strong itching of the face and a red rash. Clinical examination showed itchy papular erythema on the face and neck. No intraoral reactions or symptoms were present. The RME appliance was removed, and symptoms disappeared in 4 to 5 days. The patient was referred for a nickel patch test, which gave a strong positive result. Adverse patient reactions of potential allergic origin should be diagnosed carefully, and their possible impact on further treatment should be evaluated accordingly.

An in vitro evaluation of nickel and chromium release from different commercially available stainless steel crowns.

AIM: The aim of the present study was to estimate nickel and chromium release from commercially available stainless steel crowns (SSCs) in artificial saliva. MATERIALS AND METHODS: Ten crowns from three manufacturers were immersed in 10 ml of artificial saliva and stored in separate tubes in an incubator at 37°C for 28 days. The crowns were removed from each tube on every 7th day, and placed in other tubes with fresh artificial saliva. Flame type atomic absorption spectrophotometer was used to check for the release of metal ions in the solution inside each tube at the end of 1, 7, 14, 21, and 28 days and the control samples. RESULTS AND STATISTICAL ANALYSIS: Two-way analysis of variance and pairwise comparison using Bonferroni test was used for statistical analysis. There was statistically verified difference in the release of nickel and chromium on different days in each of the group of SSCs tested. However, no significant difference was seen in the release of both metals among the groups. CONCLUSION: In all the SSCs tested, there was the release of nickel and chromium, but the total release of both the metals even at a period of 28 days was below the critical level to cause any toxic effects. Hence, the release of metal ions should not be an alarming concern for the use of any of the group of commercially available SSCs.

Chemical, corrosion and topographical analysis of stainless steel implants after different implantation periods.

The aim of this work is to examine the corrosion properties, chemical composition, and material-implant interaction after different periods of implantation of plates used to correct funnel chest. The implants are made of 316L stainless steel. Examinations are carried out on three implants: new (nonimplanted) and two implanted for 29 and 35 months. The corrosion study reveals that in the potential range that could occur in the physiological condition the new bar has the lowest current density and the highest corrosion potential. This indicates that the new plate has the highest corrosion resistance and the corrosion resistance could be reduced during implantation by the instruments used during the operation. XPS analysis reveals changes in the surface chemistry. The longer the implantation time the more carbon and oxygen are observed and only trace of elements such as Cr, Mo are detected indicating that surface is covered by an organic layer. On some parts of the implants whitish tissue is observed: the thickness of which increased with the time of implantation. This tissue was identified as an organic layer; mainly attached to the surface on the areas close to where the implant was bent to attain anatomical fit and thus where the implant has higher surface roughness. The study indicates that the chest plates are impaired by the implantation procedure and contact with biological environment. The organic layer on the surface shows that the implant did not stay passive but some reactions at the tissue-implant interface occurred. These reactions should be seen as positive, as it indicates that the implants were accepted by the tissues. Nevertheless, if the implants react, they may continue to release chromium, nickel, and other harmful ions long term as indicated by lower corrosion resistance of the implants following implantation.