scholarly journals Late Removal of Titanium Hardware from the Elbow Is Problematic

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Abdo Bachoura ◽  
Ruriko Yoshida ◽  
Christian Lattermann ◽  
Srinath Kamineni

A retrospective review of 21 patients that underwent bone screw removal from the elbow was studied in relation to the type of metal, duration of implantation, and the location of the screws about the elbow. Screw failure during extraction was the dependent variable. Five of 21 patients experienced hardware failure during extraction. Fourteen patients had titanium alloy implants. In four cases, titanium screws broke during extraction. Compared to stainless steel, titanium screw failure during removal was not statistically significant (P=0.61). Screw removal 12 months after surgery was more likely to result in broken, retained screws in general (P=0.046) and specifically for titanium alloy (P=0.003). Bone screws removed from the distal humerus or proximal ulna had an equal chance of fracturing (P=0.28). There appears to be a time-related association of titanium alloy bone screw failure during hardware removal cases from the elbow. This may be explained by titanium’s properties and osseointegration.

1991 ◽  
Vol 4 (02) ◽  
pp. 38-45 ◽  
Author(s):  
F. Baumgart

SummaryThe so-called “mixing” of implants and instruments from different producers entertain certain risks.The use of standardized implant materials (e.g. stainless steel ISO 5832/1) from different producers is necessary but is not sufficient to justify the use of an osteosynthesis plate from one source and a bone screw from another.The design, dimensions, tolerances, manufacturing procedure, quality controls, and application technique of the instruments and implants also vary according to make. This can lead to damage, failure or fracture of the biomechanical system called “osteosynthesis” and hence the failure of the treatment undertaken. In the end, it is the patient who pays for these problems.Some examples also illustrate the potential problems for the staff and institutions involved.The use of a unique, consistent, well-tested, and approved set of implants and instruments is to be strongly recommended to avoid any additional risk.


1996 ◽  
Vol 17 (12) ◽  
pp. 742-747 ◽  
Author(s):  
David B. Thordarson ◽  
Mark J. Triffon ◽  
Michael R. Terk

Twenty-one consecutive patients with displaced talar neck fractures (12 Hawkins type II, 9 Hawkins type III) were prospectively evaluated with magnetic resonance (MR) scans performed between 3 days and 12 months after surgery. All patients underwent open reduction and internal fixation with titanium screws, except two who underwent fixation with stainless steel implants that were subsequently removed. All patients had plain radiographs. We classified the scans as follows: type A, no abnormal signal changes in the body of the talus; type B, signal changes in less than 25% of the body; type C, signal changes in 25% to 50% of the body; and type D, signal changes in greater than 50% of the body. Plain anteroposterior radiographs correlated well with MR scans in patients with type D scans, but an inconsistent correlation was noted with lesser degrees of signal changes (types A–C), with the MR scans being more accurate in displaying the volume of avascular bone. Scans obtained less than 3 weeks after injury were not helpful in assessing for avascular necrosis. We found that high-quality MR images of the talus were consistently obtained in the presence of titanium screws in contrast to images obtained with stainless steel implants. We use titanium screws in all talar neck fracture repairs, because they permit high-quality MR images. We believe that further study of patients with Hawkins type III fractures and Hawkins type II fractures with equivocal radiographic evidence of avascular necrosis is warranted to try to identify those patients at risk for collapse and perhaps to guide weightbearing recommendations.


2012 ◽  
Vol 459 ◽  
pp. 315-319 ◽  
Author(s):  
Ke Dian Wang ◽  
Wen Qiang Duan ◽  
Xue Song Mei ◽  
Wen Jun Wang

The experiments of micro-hole ablation are conducted firstly on titanium alloy Ti-6Al-4V with Nd: YAG millisecond laser. A significant factor which affects the depth of blind hole is found: the depth of recast material. This paper closely examines the regularity of recast depth varying with laser parameters, discovering that the ratio of recast depth to the entire hole depth decreases as pulse width decreases, and increases as peak power decreases. Verification experiment is conducted on stainless steel 1Cr13, eventually micro-hole with very thin recast layer is drilled when the maximum peak power and the minimum pulse width of the present millisecond laser are used.


Author(s):  
Xuejiao Shao ◽  
Juan Du ◽  
Liping Zhang ◽  
Hai Xie ◽  
Jun Tian ◽  
...  

Abstract In the code for nuclear equipment, the elasto-plastic correction factor KE is a correction factor when the stress range exceeds the yield limit for simplified elasto-plastic fatigue analysis. The parameters and expressions of KE for commonly used materials (such as austenitic stainless steel) are given in the RCC-M and ASME code, but the parameters of KE for titanium alloy materials is lacking. Based on the cyclic elasto-plastic constitutive model of Z2CND18.12 (nitrogen control) and KE parameters of austenitic stainless steel given in the code, considering various sensitive factors, a numerical calculation method for determining KE correlation coefficient is established. The elasto-plastic constitutive model of TA16 alloy with nonlinear kinematic hardening was established by the uniaxial tension, strain and stress cycling tests of TA16 titanium alloy. Based on the numerical calculation method of KE and the constitutive model of TA16 titanium alloy, the expression and correlation coefficient of KE for TA16 titanium alloy were determined.


2013 ◽  
Vol 465-466 ◽  
pp. 1060-1064 ◽  
Author(s):  
Zazuli Mohid ◽  
M.A. Liman ◽  
M.R.A. Rahman ◽  
N.H. Rafai ◽  
Erween Abdul Rahim

Welding parameters are directly influenced by the work material properties. Thermal properties such as thermal conductivity and melting point are very important to estimate the range of power required and the allowable scanning speed. However, when two or more different materials are involved, modifying lasing parameters are not enough to counter the problems such as imbalance melting region and weak adhesion of contact surface. To counter this problem, the characteristics of welding beads formation for both materials need to be clarified. In this study, comparison of welding beads constructed using the same scanning parameters were done to understand the different and similarity of melted region for the both materials. Actual welding of the both materials were done under different offset distance to obtain a balanced melting area and well mixed melting region.


Author(s):  
Sibel Akyol ◽  
Hakan Bozkus ◽  
Suzan Adin Cinar ◽  
Mehmet Murat Hanci

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