The development of a model for in vitro testing of femoral stems in impaction bone grafting

AbstractAntibiotic carrier particles of variable size might influence mechanic properties within impacted thermodisinfected and native cancellous bone different. Herafill®G containing calciumsulfate and calciumcarbonate provides high local concentrations of gentamicin being important for revision surgery in infected joint replacements. Native and thermodisinfected cancellous bone derived from 6 to 7 months old piglets was used for in vitro impaction bone grafting and supplemented each with Herafill®G granules of two different sizes. Micromovement of implants related to shear force was measured in 29 specimens distributed in 6 groups. Thermodisinfected cancellous bone revealed a significant higher shear force resistance than native bone with a mean difference of 423.8 mdeg/Nm (p < 0.001) ranging within 95% confidence interval from 181.5 to 666.0 mdeg/Nm. Adding small granules to thermodisinfected bone did not reduce shear force resistance significantly since adding large granules to native bone improved it by 344.0 mdeg/Nm (p < 0.003). Shear force resistance was found higher at the distal region of the implant compared to a proximal point of measurement throughout all specimens. Less impaction impulses were necessary for thermodisinfected bone. Thermodisinfected cancellous bone might achieve a higher degree of impaction compared with native bone resulting in increased resistance against shear force since impaction was found increased distally. Supplementation of thermodisinfected bone with small granules of Herafill®G might be considered for application of local antibiotics. Large granules appeared more beneficial for supplementation of native bone. Heterogeneity of bone graft and technical aspects of the impaction procedure have to be considered regarding the reproducibility of femoral impaction bone grafting.

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The Weibull Distribution on Reliability Evaluation of Mechanical Property for Impaction Bone Grafting

10.21203/rs.3.rs-27901/v1 ◽

2020 ◽

Author(s):

Mumingjiang Yishake ◽

Lan Tang ◽

Chenyi Ye ◽

Rongxin He

Keyword(s):

Mechanical Properties ◽

Weibull Distribution ◽

Bone Grafting ◽

Elastic Moduli ◽

High Reliability ◽

Bone Grafts ◽

Impaction Bone Grafting ◽

Large Bone

Abstract Background: The mechanical properties of bone grafts used to reconstruct defects during revision surgery, and their long-term reliability, are important in terms of treatment outcomes. However, few relevant studies have appeared. Herein, we use a new method, the Weibull distribution, to evaluate reliability.Methods: We created impacted bone grafts of two distinct sizes (7–10 mm and small slurry) using an impacting apparatus. The elastic moduli were evaluated in vitro and the Weibull moduli (m values) were calculated.Results: The elastic moduli fitted the Weibull distribution well. Large bone grafts (7–10 mm) exhibited high elastic moduli but low Weibull moduli, suggestive of poor reliability.Conclusions: The Weibull distribution was useful to evaluate the reliability of bone graft mechanical properties. A high Weibull modulus indicated high reliability and thus low variability. Both the values and reliability of mechanical properties must be considered when contemplating bone grafting.

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Influence of antibiotic pellets on pore size and shear stress resistance of impacted native and thermodisinfected cancellous bone: An in vitro femoral impaction bone grafting model

Journal of Orthopaedics ◽

10.1016/j.jor.2020.09.011 ◽

2020 ◽

Vol 22 ◽

pp. 414-421

Author(s):

C. Fölsch ◽

J. Bok ◽

G.A. Krombach ◽

M. Rickert ◽

C.A. Fonseca Ulloa ◽

...

Keyword(s):

Shear Stress ◽

Pore Size ◽

Cancellous Bone ◽

Stress Resistance ◽

Bone Grafting ◽

Impaction Bone Grafting

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Urokinase Evaluated with the Experimental Radioactive Embolus

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654164 ◽

1967 ◽

Vol 17 (03/04) ◽

pp. 405-411

Author(s):

M Hume

Keyword(s):

Animal Experiment ◽

Blood Clot ◽

In Vitro Testing ◽

Effective Agent

SummaryUrokinase and urokinase-activated plasmin have been given to the dog and rabbit. A thrombolytic state has been induced. Purified urokinase has induced lysis of the experimental radioactive blood clot embolus in the circulation. Demonstration of effectiveness in this animal experiment is hampered by inhibition of the agents in the circulation to a degree much greater than was noted in previous experiments with streptokinase. In vitro testing indicates that under proper conditions urokinase will be an effective agent in the treatment of human thromboembolism.

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