Tensile Fatigue Failure of Acrylic Bone Cement

1983 ◽  
Vol 105 (4) ◽  
pp. 393-397 ◽  
Author(s):  
E. I. Gates ◽  
D. R. Carter ◽  
W. H. Harris
Keyword(s):  
Bone Cement ◽  
Fatigue Failure ◽  
Critical Role ◽  
Constant Strain Rate ◽  
Fatigue Tests ◽  
Acrylic Bone Cement ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Tensile Fatigue ◽  
Number Of Cycles

Tensile fatigue tests of acrylic bone cement were conducted under strain control in a wet environment at 37°C. A constant strain rate of 0.02s−1 was used, resulting in physiologic loading frequencies. Comparison of the tensile fatigue data with the results of previous tension-compression fatigue tests indicates that fatigue failure is governed primarily by the maximum cyclic tensile strain. The compressive portion of the loading cycle has little effect on the number of cycles to failure. A new empirically derived equation is introduced to describe the influence of mean strain and strain amplitude on fatigue endurance. The results emphasize the critical role tensile strains may play in cement failure and loosening of total joint replacements.

Biomineralization of Glass Fibre Reinforced Porous Acrylic Bone Cement

2007 ◽  
Vol 330-332 ◽  
pp. 815-818 ◽  
Author(s):  
Mervi Puska ◽  
Ari-Pekka Forsback ◽  
Antti Yli-Urpo ◽  
Jukka Seppälä ◽  
Pekka K. Vallittu
Keyword(s):  
Bone Cement ◽  
Bone Ingrowth ◽  
In Vitro Study ◽  
Biological Properties ◽  
Cement Matrix ◽  
Acrylic Bone Cement ◽  
Joint Replacements ◽  
Glass Fibre Reinforced

Acrylic bone cements are used to fix joint replacements to bone. The main substance in acrylic bone cement is biologically inert poly(methylmethacrylate), PMMA. The dense PMMA polymer structure of cement does not allow bone ingrowth into cement. Therefore, the main focus of our studies is to modify acrylic bone cement in order to improve its biological properties e.g., by creating porosity in the cement matrix. The porous structure is in situ created using pore-generating filler (i.e., 20 wt% of an experimental biodegradable polyamide) that is incorporated in acrylic bone cement. The aim of this in vitro study was to investigate the biomineralization of acrylic bone cement modified using an experimental biodegradable polyamide.

Influence of Exogenous Variables on Intrusion Depth of PMMA Bone Cement: Revision of ISO 5833 Standard

2020 ◽  
Vol 3 (3) ◽  
pp. 189-196
Author(s):  
Gladius Lewis ◽  
Liang Zhang
Keyword(s):  
Bone Cement ◽  
Vacuum Chamber ◽  
High Viscosity ◽  
Storage Medium ◽  
Joint Replacements ◽  
Total Joint Replacements ◽  
Pmma Bone Cement ◽  
Relevant Variables ◽  
Intrusion Depth ◽  
Curing Cement

Background: Poly (methyl methacrylate) (PMMA) bone cement is widely used to anchor total joint replacements to the contiguous bone. Among the clinically-relevant properties of this material is its intrusion depth (ID) because it indicates the potential for interdigitation of the curing cement into the interstices of the cancellous bone. ID is determined using procedures stipulated in ISO 5833. There is only one study in which ISO 5833 was examined critically, but only one exogenous variable was considered. Purpose: We carried out an extensive critical analysis of the ISO 5833 Standard with a view to making recommendations for revising it. Materials and Methods: 7 approved PMMA bone cement brands (covering low-, medium-, and high-viscosity brands) were used in two series of tests. In the first series, the influence of time at which ID was determined (relative to achievement of cement doughing time (DT)) was delineated. In the second series, the influence of three clinically-relevant variables on ID for each of these brands was determined and, then, response surface methodology was used to analyze the results. Results: ID results are given for both series of tests. Over the range of the variables used, the optimum IDs for a low-, medium-, and high-viscosity brand were computed to be 5.7 mm, 3.1 mm, and 2.4 mm, respectively. Conclusion: The findings allowed us to recommend that the following revisions be made to stipulations in ISO 5833 for determining ID: prior to running the ID test, store the cement unit at 1°C; 60 minutes after removing the cement unit from the storage medium, mix the cement powder and liquid, in a vacuum chamber, at 120 rpm; and determine ID 3 minutes after DT is achieved.

scholarly journals Fatigue Properties of AZ31B Magnesium Alloy Processed by Equal-Channel Angular Pressing

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1191
Author(s):  
Ryuichi Yamada ◽  
Shoichiro Yoshihara ◽  
Yasumi Ito
Keyword(s):  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Low Cycle Fatigue ◽  
Annealed Sample ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Angular Pressing ◽  
Fundamental Research ◽  
Number Of Cycles ◽  
Biodegradable Magnesium

A stent is employed to expand a narrowed tubular organ, such as a blood vessel. However, the persistent presence of a stainless steel stent yields several problems of late thrombosis, restenosis and chronic inflammation reactions. Biodegradable magnesium stents have been introduced to solve these problems. However, magnesium-based alloys suffer from poor ductility and lower than desired fatigue performance. There is still a huge demand for further research on new alloys and stent designs. Then, as fundamental research for this, AZ31 B magnesium alloy has been investigated for the effect of equal-channel angular pressing on the fatigue properties. ECAP was conducted for one pass and eight passes at 300 °C using a die with a channel angle of 90°. An annealed sample and ECAP sample of AZ31 B magnesium alloy were subjected to tensile and fatigue tests. As a result of the tensile test, strength in the ECAP (one pass) sample was higher than in the annealed sample. As a result of the fatigue test, at stress amplitude σa = 100 MPa, the number of cycles to failure was largest in the annealed sample, medium in the ECAP (one pass) sample and lowest in the ECAP (eight passes) sample. It was suggested that the small low cycle fatigue life of the ECAP (eight passes) sample is attributable to severe plastic deformation.

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