Wire Fracture Research Articles

Minimally invasive technique of tension band wiring in patella fractures

Introduction: Patellar fractures constitute 1% of all skeletal fractures. Traditionally they are operated by open technique. In today’s world of minimally invasive surgery, doing open technique of wiring seems less justified for this percutaneously palpable bone fracture particularly in transverse fractures. Hence, we developed a technique of percutaneous fixation of transverse displaced patella fracture not described yet using parallel K wires and tension band wiring principle and carried out a study to analyze its results Methods: Prospective study was carried out at Mimer Medical College. 20 males and 12 females with transverse fractures of the patella were selected for operation with minimally invasive technique of tension band wiring. Patients were evaluated for range of motion, pain, operating time and complications at four months post operation. Results: 32 patients underwent tension band wiring successfully. Radiological time for union was 10.2+/- 1.8 weeks also had nearly full range of motion. Average operating time was only 40.5 minutes. No patient developed infection and there was no wire breakage and irritation. VAS scores were good and power of quadriceps was also good. Conclusion: Minimally invasive technique of tension band wiring in patella fractures gives encouraging results.

Evaluation of functional outcome of tension band wiring in olecranon fractures and factors affecting the overall functional outcome

Aim: The aim of this study is to evaluate the functional outcomes of olecranon fractures treated with tension band wiring and factors affecting it. Materials and methods: this study consisted of 30 patients with olecranon fractures aged between 18-48 years. Minimum follow up of 1 year was done. Results were assessed radiologically and clinically using mayo elbow performance score. Also some factors that affected the outcome were also noted. Result: mean postoperative range of motion after tension band wiring was 1080 (range 800-1400). Functional outcome was excellent in 18, good in 8, fair in 2 and poor in 2 according to the Mayo elbow performance score (MEPS). The average time taken for union was 7 weeks (range 4-12 weeks). Young men with non comminuted, transverse facture, with small proximal fragment of olecranon and those compliant to early physiotherapy showed better outcomes Conclusion: Tension band wiring is effective method of fixation in terms of union and elbow movements. Factors like age sex compliance to physiotherapy and type of fracture surely affect the final functional outcomes.

TCTAP C-109 Guide Wire Fracture with Remnant Filaments in Left Main Coronary Artery During Chronic Total Occlusion Intervention: Wire Intertwining Retrieval Technique

### Patient Initials or Identifier Number WP ### Relevant Clinical History and Physical Exam Angina CCS 2 one month ago. Refractory hypertension. History of ACS 9 months ago (non-revascularized). Physical exams : BP 152/94; HR 78 bpm; RR 18x/mins, other exam within normal limit ### Relevant Test

Assessment of Structure Integrity and Mechanical Properties of Carbon Steel Wire in Combined Deformation Processing

Because basic metal forming methods have reached the maximum of their manufacturing capabilities in deformation-velocity processing modes so called combined or integrated processing methods move to the forefront. The method of combined deformation processing based on drawing with bending and torsion deformation was developed. On the example of carbon steel wire it was shown that microstructure and mechanical properties can vary in a wide range depending on the process regimes. In order to estimate the probability of carbon steel wire fracture at the designed combined deformation processing the simulation complex DEFORM-3D was used. The results demonstrate that there are no areas with high concentrations of hydrostatic pressure and overestimated values Cockcroft-Latham criterion. For the developed combined deformation processing of wire by drawing with alternating bending and torsion, algorithm for the prediction of carbon steel wire microstructure and mechanical properties changing at combined deformation processing was carried out. The developed methodological approach to forecasting of formation of the structure and mechanical properties during combined deformation processing of carbon steel can be used to solve both direct and inverse problems.

Finite element analysis of hydrogen effects on superelastic NiTi shape memory alloys: Orthodontic application

Thanks to its greater flexibility and biocompatibility with human tissue, superelastic NiTi alloys have taken an important part in the market of orthodontic wires. However, wire fractures and superelasticity losses are notified after a few months from being fixed in the teeth. This behavior is due to the hydrogen presence in the oral cavity, which brittles the NiTi arch wire. In this article, a diffusion-mechanical coupled model is presented while considering the hydrogen influences on the NiTi superelasticity. The model is integrated in ABAQUS finite element software via a UMAT subroutine. Additionally, a finite element model of a deflected orthodontic NiTi wire within three teeth brackets is simulated in the presence of hydrogen. The numerical results demonstrate that the force applied to the tooth drops with respect to the increase in the hydrogen amount. This behavior is attributed to the expansion of the NiTi structure after absorbing hydrogen. In addition, it is shown that hydrogen induces a loss of superelasticity. Hence, it attenuates the role of the orthodontic wire on the correction tooth malposition.

Effect of Modeling Variables upon Projection of Corrosion-Induced Bridge Post-Tension Tendon Failures

Construction via post-tensioning (PT) has evolved over the past 60 y as an often preferred approach to affecting integrity for large concrete structures. In the case of bridges, tendon ducts typically contain multiple 15.24 mm (0.600 in) diameter, seven wire strands of minimum tensile strength 1,960 kN (270 ksi), and are invariably grouted. However, failures have been reported as a consequence of corrosion caused by either chemically or physically deficient grout. In response to this a methodology was developed and reported whereby the timing of wire and strand fractures and tendon failures can be projected. The present paper reviews basics of the modeling approach and evaluates the influence of modeling variables upon failure projections. These variables include the following: (1) analysis variables (generation of random numbers), (2) strand/tendon stress, (3) wire/strand strength, (4) number of tendons, and (5) tendon length. The significance of each is discussed and results are related to the timing of tendon failures on bridge structures.

Developing an objective assessment of surgical performance from operating room video and surgical imagery

ABSTRACTAn unbiased, repeatable process for assessing operating room performance is an important step toward quantifying the relationship between surgical training and performance. Hip fracture surgeries offer a promising first target in orthopedic trauma because they are common and they offer quantitative performance metrics that can be assessed from video recordings and intraoperative fluoroscopic images. Hip fracture repair surgeries were recorded using a head-mounted point-of-view camera. Intraoperative fluoroscopic images were also saved. The following performance metrics were analyzed: duration of wire navigation, number of fluoroscopic images collected, degree of intervention by the surgeon's supervisor, and the tip-apex distance (TAD). Two orthopedic traumatologists graded surgical performance in each video independently using an Skills (OSATS). Wire navigation duration correlated with weeks into residency and prior cases logged. TAD correlated with cases logged. There was no significant correlation between the OSATS total score and experience metrics. Total OSATS score correlated with duration and number of fluoroscopic images. Our results indicate that two metrics of hip fracture wire navigation performance—duration and TAD—significantly differentiate surgical experience. The methods presented have the potential to provide truly objective assessment of resident technical performance in the OR.

Деформация и разрушение аморфных и кристаллических проводов медицинского назначения при кручении

Деформация и разрушение аморфных и кристаллических проводов медицинского назначения при кручении

Total hip replacement in sickle cell disorder: A preliminary report of challenges and early outcome of 21 consecutive patients

The aim of this study is to describe the pattern of presentation osteoarthritic patients with sickle cell disorder (SCD) in our environment, determine the implant sizes taking the peculiar nature of the pathology and our operating environment into consideration, highlight the challenges and technical difficulties encountered during the procedure, measure the functional outcome and observe complications of treatment, recommend ways of improving outcome. Between November 2008 and November 2012, 29 consecutive primary total hip replacements (THRs) were performed on 21 patients with avascular necrosis of the head of femur secondary to SCD. Patients' evaluation was performed at two different times of follow-up (1 and 5 years, respectively). Twenty-one patients were available at 1 year as well as 5-year follow-up. The mean preoperative Harris Hip Score was 20.17 ± 11. The mean postoperative Harris Hip Score was 92.25 ± 13 (P < 0.001) at 1 year and 88.75 ± 10 (P < 0.001) at 5 years. Eighteen patients had regional anesthesia while three had general anesthesia. The average cup size used was 49.43 with a range of 46-54. The average liner size was 49.43 with a range of 46-54. The head size used in all patients was 28. The average stem size was 6.57 with a range of 6-8. The offset used in all the patients was standard All the patients had 1-2 screw fixation of the acetabular shell. Four patients had complications as follows: periprosthetic fracture 1, superficial wound infection 1, pulmonary complication 1, and abdominal crisis 1. THR is a veritable means of treatment of patients with avascular necrosis of the femoral head arising from SCDs. The challenges encountered during the surgery are related to the quality of bone of the affected patient. Arthroplasty Surgeons in our environment must be fully prepared for the challenges by ensuring a preoperative plan that will take care of the technical problems such as recreating femoral canals, wiring of intraoperative fractures as well as treatment of acetabular defects. A detailed planned total hip arthroplasty can be performed in patients with SCD in younger patients with good clinical benefits.

Analysis of fatigue life of the steel cord used in tires in unidirectional and bidirectional bending

The results of fatigue life tests of steel cord used in construction machinery tires are presented in this paper. Steel wire used in tires, called the steel cord, is largely responsible for transferring large loads, but unfortunately it quickly undergoes fatigue. The fatigue life of this steel cord is influenced by many factors related to its construction, workmanship quality, as well as the method of bending during each working cycle. In laboratory tests, the fatigue life of steel cords was compared in the conditions of unidirectional and bidirectional bending, on a specially built, innovative fatigue testing machine for steel cords. In fatigue life tests, a fundamental difference is visible in the number of cycles leading to breaking. For one-way bending process, the number of cycles is significantly greater than for the bidirectional bending. Instead of the wire fracture process, a steel cord elongation process takes place that increases the number of fatigue cycles, which is reflected directly in the number of failures in the tires of construction machines

Deformability of Oxide Inclusions in Tire Cord Steels

The deformation of oxide inclusions in tire cord steels during hot rolling was analyzed, and the factors influencing their deformability at high and low temperatures were evaluated and discussed. The aspect ratio of oxide inclusions decreased with the increasing reduction ratio of the steel during hot rolling owing to the fracture of the inclusions. The aspect ratio obtained after the first hot-rolling process was used to characterize the high-temperature deformability of the inclusions. The deformation first increased and then decreased with the increasing (MgO + Al2O3)/(SiO2 + MnO) ratio of the inclusions. It also increased with the decreasing melting temperatures of the inclusions. Young’s modulus was used to evaluate the low-temperature deformability of the inclusions. An empirical formula was fitted to calculate the Young’s moduli of the oxides using the mean atomic volume. The moduli values of the inclusions causing wire fracture were significantly greater than the average. To reduce fracture in tire cord steel wires during cold drawing, it is proposed that inclusions be controlled to those with high SiO2 content and extremely low Al2O3 content. This proposal is based on the hypothesis that the deformabilities of oxides during cold drawing are inversely proportional to their Young’s moduli. The future study thus proposed includes an experimental confirmation for the abovementioned predictions.

Research on Electromagnetic NDE Inspection Method for Broken Wire of PCCP

预应力钢筒混凝土管(Pre-stressed Concrete Cylinder Pipe, PCCP)作为一种新型的输水管材，被广泛应用于水利工程。在PCCP运行过程中，环境腐蚀或操作不当会导致管内高强钢丝的腐蚀或断裂，进而导致泄漏、爆管等事故。目前国内外普遍采用电磁涡流检测技术，对PCCP的断丝与金属管壁健康状态进行无损检测，检测系统在管内运行并配合计程轮等工具实现断丝位置的定位。本文针对国内外两种常用的PCCP断丝电磁检测技术，即远场涡流检测方法和正交电磁检测方法，建立了简化分析模型，并给出了等效交流电路，通过仿真分析验证了模型的正确性。分析了电磁检测频率的选取原则，建议选取23 Hz作为检测频率。给出了电磁检测系统的设计与实现，并经过了管道断丝试验验证，有效提取了故障特征。 Pre-stressed Concrete Cylinder Pipe (PCCP), as a new type of pipeline for water delivery, has been widely used in water conservancy projects. During the operation of PCCP, environmental corrosion or improper operation will lead to corrosion or fracture of high-strength steel wire in the pipe, resulting in leakage, explosion and other accidents. Currently some nondestructive methods, such as electromagnetic eddy current inspection method, are widely used to test the broken wire and assess the health PCCP, and equipped with a counting-wheel or other tools to achieve the localization of broken wires. This paper presents a simple model of two famous electromagnetic detection technologies for PCCP broken wire, i.e. the remote field eddy current testing method and orthogonal electromagnetic detection method. Also the equivalent AC circuit is given. By simulation analysis the simple model is verified. The selection principle of electromagnetic detection frequency is analyzed, and 23 Hz is selected as the detection frequency. The design and implementation of the electromagnetic detection system are given, and the fault characteristics are effectively extracted through the broken wire tests.

Influence Length of Wire Fracture and Wire-to-Wire Interaction in Helically Wired Strands under Axial Loads

Influence Length of Wire Fracture and Wire-to-Wire Interaction in Helically Wired Strands under Axial Loads

A novel miniature, wireless neurostimulator in the management of chronic craniofacial pain: Preliminary results from a prospective pilot study

ObjectiveTo report a novel wireless neuromodulation system for treatment of refractory craniofacial pain. BackgroundPrevious studies utilizing peripheral nerve stimulation (PNS) of the occipital and trigeminal nerves reported positive outcomes for alleviating neuropathic pain localized to the craniofacial and occipital areas. However several technological limitations and cosmetic concerns inhibited a more widespread acceptance and use of neuromodulation. Also, a relatively high incidence of adverse events like electrode erosions, dislocation, wire fracture and/or infection at the surgical site mandates a change in our approach to neuromodulation technology and implant techniques in the craniofacial region. MethodsWe report a novel approach for the management of craniofacial pain with a wirelessly powered, minimally invasive PNS system. The system is percutaneously implanted and placed subcutaneously adjacent to affected facial nerves via visual guidance by the clinician. In this feasibility study, pilot evidence was gathered in a cohort of ten subjects suffering from a combination of chronic headaches, facial pain for at least 15 days per month and for at least 4h/day. ResultsAt four weeks post-implant follow up, all patients reported sustained pain relief of the primary pain area. Electrode location and total number of electrodes used per subject varied across the cohort. The average pain reduction using the visual analog scale was ≥82%. The procedure had no adverse events or side effects. ConclusionPercutaneous placement of a wireless neurostimulation device directly adjacent to affected craniofacial nerve(s) is a minimally invasive and reversible method of pain control in patients with craniofacial pain refractory to conventional medical managements. Preliminary results are encouraging and further larger scale studies are required for improved applications.

Is the novel olecranon tension plate a valid alternative to tension band wiring of olecranon fractures? A biomechanical study on cadaver bones.

Tension band wiring (TBW) used for olecranon fractures is afflicted with a high rate of complications. The aim of this study was to compare the stability of the TBW versus an alternative, novel low-profile olecranon tension plate (OTP) with angular stable screws in a simulated complex fracture model. Nine fresh-frozen pairs of cadaver proximal ulnae with an oblique osteotomy and an additional wedge fragment simulating an unstable fracture were tested. The TBW and OTP were implanted pairwise. The elbow motion was simulated in a single-muscle model and ranged from full extension to 90° of flexion. The pulling force of the triceps tendon ranged from 50 to 200N. The displacement of the fracture fragments was measured with a video motion analysis system over 304 cycles. Data were assessed statistically using the Wilcoxon signed-rank test. The cyclic loading tests showed mean loosening of the fracture fragments at the articular surface of 0.56mm using TBW (SD 0.65) and 0.15mm for OTP (SD 0.39). There was no statistical significance in loosening between the two constructs (p=0.31). No plate breakage or screw loosening occurred. The low-profile OTP, using the principles of pre-tensioning, lag, cortical, and angular stable screws together, demonstrated similar stability after olecranon fracture fixation when compared with the TBW technique and a lag screw in the olecranon fracture model with a third wedge fragment.

Deformation mechanisms in submicron Be wires

Abstract

Modeling and Projecting the Onset and Subsequent Failure Rate of Corroding Bridge Post-Tension Tendons Arising from Deficient Grout

Post-tensioning (PT) has become an important approach to affecting integrity of large reinforced concrete structures, including bridges. While there are a number of advantages to PT construction compared to conventional reinforcement, corrosion caused bridge tendon failures have recently been reported, in some cases within but a few years of construction, as a consequence of either chemically or physically deficient grout (or a combination of the two), where the former involves elevated concentration of chlorides or free sulfates (or both) and the latter voids with free water, and soft, chalky, segregated, separated grout. The present paper reviews a predictive model that was developed to project the onset and subsequent rate of wire and strand fractures and tendon failures as a function of time, given information regarding the present extent of corrosion. Inputs to the model are the mean and standard deviation of, first, remaining cross-section area at the most corroded location on individual wires and, second, an experimentally determined relationship between residual fracture stress and remaining cross-section area of corroded wires, both of which are represented as distributions. Particular emphasis is placed upon fracture and failure rates subsequent to first occurrence, because these can provide useful information for assuring timely intervention and integrity assurance of PT structures with corrosion issues. The results indicate that tendon failures, once initiated, can occur at an unmanageable rate even for relatively modest rates of corrosion.

Outcomes of dynamic hip screw augmented with trochanteric wiring for treatment of unstable type A2 intertrochanteric femur fractures

BackgroundPosteromedial and greater trochanteric fragments are a major cause of telescoping and medialization of the femoral shaft in an unstable intertrochanteric fracture. This leads to significant limb shortening, fracture collapse in varus position and implant failure, which can be prevented by trochanteric wiring in addition to dynamic hip screw (DHS) fixation. The purpose of our study is to assess the outcomes of DHS augmented with trochanteric wiring in unstable type A2 intertrochanteric fractures. Materials and methodsOne hundred and two retrospective cases of unstable intertrochanteric fractures treated with DHS between January 2010 and December 2015 with a minimum follow-up period of 12 months were reviewed. Out of 102 cases, 28 were treated with DHS and derotation screw alone (Group A), while in rest 74 cases trochanteric wiring was used as an augmentation to DHS and derotation screw (Group B). Patients were evaluated clinically for range of motion, Harris hip score and Oxford hip score. Radiologically, fracture reduction, change in neck shaft angle and neck length ratio in comparison to opposite hip and union status of greater trochanter were assessed. ResultsThe mean age of the patients at the time of surgery was 72 years (range 23–94 years) with 48 males and 54 females. The mean follow-up period was 20 months (range 12–48 months). The Harris hip score, Oxford hip score, shortening, attainment of weight bearing and change in neck shaft angle was not significantly different between the two groups (all p values >0.05). Incidence of greater trochanter nonunion was greater in group A (17.85%) as compared to group B (6.75%). We found significant association between occurrence of limp with varus change in neck shaft angle, decrease in neck length ratio and greater trochanteric non-union (all p values <0.05). We had 7 complications, one superficial infection, one deep vein thrombosis, 4 screw cut out and one deep infection treated with implant removal. ConclusionDHS augmented with trochanteric wiring in unstable intertrochanteric fractures gives similar result to group without no wiring, although greater trochanter non-union rate was more in the latter group. Limp can be prevented by anatomical or valgus fixation, augmentation of DHS to support posteromedial and greater trochanteric fragments and delayed weight bearing.

Vertical and figure of eight fibre wiring for patella fractures

Background: Displaced patella fractures need to be treated by internal fixation for achieving good outcome. Metallic hardware related pain and irritation are one among the many reasons for reoperations. Fracture displacement can happen due to early mobilisation depending on bone quality and fracture pattern. The aim of our study was to evaluate the postoperative outcome and complication rates of patella fractures fixed with fibre wires in a vertical and figure of eight pattern. Methods: We retrospectively followed up all patella fractures fixed using fibre wires utilising Krackow stitches through patellar tendon, longitudinal fixation through fracture fragments and figure of eight wiring on anterior patella. We evaluated their clinical outcome, range of movement, time to union and complication rates. We also evaluated these for arthritic scenario and different fracture patterns. Results: We had 22 patients (mean age 50.7) with a mean follow up of 22.7 months, mean Bostman score of 23.5, mean range of movement 1150 and mean time to union 13.5 weeks. Arthritic patients though united without any complications had an unsatisfactory score. None of the patients developed any hardware related complications, fracture displacement or needed an implant removal. Conclusion: Fibre wires can be used in vertical and figure of pattern for achieving fracture union with good clinical outcome without fracture displacement or symptomatic hardware problems.

Microstructure, mechanical behaviour and fracture of pure tungsten wire after different heat treatments

Plastic deformation of tungsten wire is an effective source of toughening tungsten fibre-reinforced tungsten composites (Wf/W) and other tungsten fibre-reinforced composites. To provide a reference for optimization of those composites, unconstrained pure tungsten wire is studied after various heat treatments in terms of microstructure, mechanical behaviour and fracture mode. Recrystallization is already observed at a relatively low temperature of 1273K due to the large driving force caused by a high dislocation density. Annealing for 30min at 1900K also leads to recrystallization, but causes a rather different microstructure. As-fabricated wire and wire recrystallized at 1273K for 3h show fine grains with a high aspect ratio and a substantial plastic deformability: a clearly defined tensile strength, high plastic work, similar necking shape, and the characteristic knife-edge-necking of individual grains on the fracture surface. While the wire recrystallized at 1900K displays large, almost equiaxed grains with low aspect ratios as well as distinct brittle properties. Therefore, it is suggested that a high aspect ratio of the grains is important for the ductile behaviour of tungsten wire and that embrittlement is caused by the loss of the preferable elongated grain structure rather than by recrystallization. In addition, a detailed evaluation of the plastic deformation behaviour during tensile test gives guidance to the design and optimization of tungsten fibre-reinforced composites.