Study on cutting force of reaming porcine bone and substitute bone

2021 ◽  
pp. 095441192110437
Author(s):  
Zhihua Liu ◽  
Jianbo Sui ◽  
Bin Chen ◽  
Zhishan Yuan ◽  
Cezhi Du ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Force Characteristic ◽  
Successful Implementation ◽  
Feed Speed ◽  
Feedback Systems ◽  
Protection Mechanism ◽  
High Feed ◽  
Assistant Systems ◽  
Realistic Force

Accurate mechanical feedback systems are critical to the successful implementation of virtual and robotic surgical assistant systems. Experimental measurements of reaming force could further our understanding of the cancellous bone reaming process during hip arthroplasty to help develop surgical simulators with realistic force effects and improve the protection mechanism of robot-assisted surgical systems. In this study, reaming experiments with natural bone (porcine femur) and a bone substitute (polyurethane blocks) were performed on a CNC lathe. This paper proposes using the maximum reaming force of the steady reaming stage to represent the force characteristic. The reaming force is biased to one side in the overlap direction and the maximum reaming force will vary when the reamer is not coincident with the long axis of the bone. The diameter of the reamer has the greatest influence on reaming force, which clearly increases with increasing reamer diameter. During operation, a medium rotation speed and high feed speed can reduce the reaming force. After cutting, the morphology of the cut surface is not flat, but arc-shaped, which will have a significant impact on implantation of the femoral prosthesis. In in vitro cutting experiments, polyurethane blocks can be used as a substitute for cancellous bone.

Clinical dilemmas of routine outcome monitoring and clinical feedback: a qualitative study of patient experiences

2020 ◽  
Author(s):  
Stig Magne Solstad ◽  
Gøril Kleiven Solberg ◽  
Louis George Castonguay ◽  
Christian Moltu
Keyword(s):  
Mental Health ◽  
Clinical Skill ◽  
Routine Outcome Monitoring ◽  
Future Research ◽  
Successful Implementation ◽  
Basic Training ◽  
Feedback Systems ◽  
Clinical Encounters ◽  
Outcome Monitoring ◽  
Clinical Feedback

Purpose: Routine outcome monitoring (ROM) and clinical feedback systems (CFS) are becoming prevalent in mental health services. The field faces several challenges to successful implementation. The purpose of this study is to gain a better understanding of these challenges by exploring the patient perspective. Method: We report the findings from a qualitative, video assisted interview study of 12 patients from a Norwegian mental health outpatient clinic using ROM/CFS. Results: Our analysis resulted in three pairs of opposing experiences with using ROM/CFS: 1) Explicit vs. implicit use of CFS information, 2) CFS directing focus towards- vs. directing focus away from therapeutic topics and 3) Giving vs. receiving feedback. None of these were intrinsically helpful or hindering. Participants had vastly differing preferences for how to use ROM/CFS in clinical encounters, but all needed the information to be used in a meaningful way by their therapists. If not, ROM/CFS was at risk of becoming meaningless and hindering for therapy. Conclusion: These findings confirm and provide further nuance to previous research. We propose to consider ROM/CFS a clinical skill that should be a part of basic training for therapists. How to use and implement ROM/CFS skillfully should also be the focus of future research.

scholarly journals Ibudilast Mitigates Delayed Bone Healing Caused by Lipopolysaccharide by Altering Osteoblast and Osteoclast Activity

2021 ◽  
Vol 22 (3) ◽  
pp. 1169
Author(s):  
Yuhan Chang ◽  
Chih-Chien Hu ◽  
Ying-Yu Wu ◽  
Steve W. N. Ueng ◽  
Chih-Hsiang Chang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bone Formation ◽  
Cancellous Bone ◽  
Bone Healing ◽  
Bone Bridge ◽  
Cell Wall Components ◽  
Osteoclast Activity ◽  
Wall Components

Bacterial infection in orthopedic surgery is challenging because cell wall components released after bactericidal treatment can alter osteoblast and osteoclast activity and impair fracture stability. However, the precise effects and mechanisms whereby cell wall components impair bone healing are unclear. In this study, we characterized the effects of lipopolysaccharide (LPS) on bone healing and osteoclast and osteoblast activity in vitro and in vivo and evaluated the effects of ibudilast, an antagonist of toll-like receptor 4 (TLR4), on LPS-induced changes. In particular, micro-computed tomography was used to reconstruct femoral morphology and analyze callus bone content in a femoral defect mouse model. In the sham-treated group, significant bone bridge and cancellous bone formation were observed after surgery, however, LPS treatment delayed bone bridge and cancellous bone formation. LPS inhibited osteogenic factor-induced MC3T3-E1 cell differentiation, alkaline phosphatase (ALP) levels, calcium deposition, and osteopontin secretion and increased the activity of osteoclast-associated molecules, including cathepsin K and tartrate-resistant acid phosphatase in vitro. Finally, ibudilast blocked the LPS-induced inhibition of osteoblast activation and activation of osteoclast in vitro and attenuated LPS-induced delayed callus bone formation in vivo. Our results provide a basis for the development of a novel strategy for the treatment of bone infection.

scholarly journals Effect of synthetic bone replacement material of different size on shear stress resistance within impacted native and thermodisinfected cancellous bone: an in vitro femoral impaction bone grafting model

2021 ◽  
Author(s):  
C. Fölsch ◽  
P. Sahm ◽  
C. A. Fonseca Ulloa ◽  
G. A. Krombach ◽  
M. Kampschulte ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Bone Grafting ◽  
Shear Force ◽  
Distal Region ◽  
Impaction Bone Grafting ◽  
Proximal Point ◽  
Local Antibiotics ◽  
Joint Replacements ◽  
Native Bone

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.

Primary Stability of Short Implants Inserted Using Piezoelectric or Drilling Systems: An In Vitro Comparison

2019 ◽  
Vol 45 (4) ◽  
pp. 259-266
Author(s):  
Claudio Stacchi ◽  
Matteo De Biasi ◽  
Lucio Torelli ◽  
Massimo Robiony ◽  
Roberto Di Lenarda ◽  
...  
Keyword(s):  
Cancellous Bone ◽  
Operative Time ◽  
Primary Stability ◽  
Site Preparation ◽  
Preparation Technique ◽  
Implant Stability ◽  
Implant Stability Quotient ◽  
Custom Made ◽  
Implant Site Preparation

The primary objective of the present in vitro study was to evaluate the influence of implant site preparation technique (drills vs ultrasonic instrumentation) on the primary stability of short dental implants with two different designs inserted in simulated low-quality cancellous bone. Eighty implant sites were prepared in custom-made solid rigid polyurethane blocks with two different low cancellous bone densities (5 or 15 pounds per cubic foot [PCF]), equally distributed between piezoelectric (Surgysonic Moto, Esacrom, Italy) and conventional drilling techniques. Two short implant systems (Prama and Syra, Sweden & Martina) were tested by inserting 40 fixtures of each system (both 6.0 mm length and 5.0 mm diameter), divided in the four subgroups (drills/5 PCF density; drills/15 PCF density; piezo/5 PCF density; piezo/15 PCF density). Insertion torque (Ncm), implant stability quotient values, removal torque (Ncm), and surgical time were recorded. Data were analyzed by 3-way ANOVA and Scheffé's test (α = 0.05). With slight variations among the considered dependent variables, overall high primary implant stability was observed across all subgroups. Piezoelectric instrumentation allowed for comparable or slightly superior primary stability in comparison with the drilling procedures in both implant systems. The Prama implants group showed the highest mean reverse torque and Syra implants the highest implant stability quotient values. Piezoelectric implant site preparation took prolonged operative time compared to conventional preparation with drills; among the drilling procedures, Syra system required fewer surgical steps and shorter operative time.

scholarly journals Phosphorylation of Serine 303 Is a Prerequisite for the Stress-Inducible SUMO Modification of Heat Shock Factor 1

2003 ◽  
Vol 23 (8) ◽  
pp. 2953-2968 ◽  
Author(s):  
Ville Hietakangas ◽  
Johanna K. Ahlskog ◽  
Annika M. Jakobsson ◽  
Maria Hellesuo ◽  
Niko M. Sahlberg ◽  
...  
Keyword(s):  
Heat Shock ◽  
Phosphorylation Site ◽  
Stress Granules ◽  
Heat Shock Factor ◽  
Transcriptional Level ◽  
Heat Shock Factor 1 ◽  
Protection Mechanism ◽  
Sumo Modification

ABSTRACT The heat shock response, which is accompanied by a rapid and robust upregulation of heat shock proteins (Hsps), is a highly conserved protection mechanism against protein-damaging stress. Hsp induction is mainly regulated at transcriptional level by stress-inducible heat shock factor 1 (HSF1). Upon activation, HSF1 trimerizes, binds to DNA, concentrates in the nuclear stress granules, and undergoes a marked multisite phosphorylation, which correlates with its transcriptional activity. In this study, we show that HSF1 is modified by SUMO-1 and SUMO-2 in a stress-inducible manner. Sumoylation is rapidly and transiently enhanced on lysine 298, located in the regulatory domain of HSF1, adjacent to several critical phosphorylation sites. Sumoylation analyses of HSF1 phosphorylation site mutants reveal that specifically the phosphorylation-deficient S303 mutant remains devoid of SUMO modification in vivo and the mutant mimicking phosphorylation of S303 promotes HSF1 sumoylation in vitro, indicating that S303 phosphorylation is required for K298 sumoylation. This finding is further supported by phosphopeptide mapping and analysis with S303/7 phosphospecific antibodies, which demonstrate that serine 303 is a target for strong heat-inducible phosphorylation, corresponding to the inducible HSF1 sumoylation. A transient phosphorylation-dependent colocalization of HSF1 and SUMO-1 in nuclear stress granules provides evidence for a strictly regulated subnuclear interplay between HSF1 and SUMO.

A combined model of ultrasound velocity and BMD improves cancellous bone strength prediction in vitro

1996 ◽  
Vol 6 (S1) ◽  
pp. 196-196 ◽  
Author(s):  
C. F. Njeh ◽  
C. W. Kuo ◽  
C. M. Boivin ◽  
C. M. Langton
Keyword(s):  
Bone Strength ◽  
Cancellous Bone ◽  
Ultrasound Velocity ◽  
Strength Prediction ◽  
Combined Model

Influence of cancellous bone microstructure on two ultrasonic wave propagations in bovine femur: An in vitro study

2010 ◽  
Vol 128 (5) ◽  
pp. 3181-3189 ◽  
Author(s):  
Katsunori Mizuno ◽  
Hiroki Somiya ◽  
Tomohiro Kubo ◽  
Mami Matsukawa ◽  
Takahiko Otani ◽  
...  
Keyword(s):  
Ultrasonic Wave ◽  
Cancellous Bone ◽  
In Vitro Study ◽  
Bone Microstructure ◽  
Vitro Study

scholarly journals Osteopontin Deficiency Induces Parathyroid Hormone Enhancement of Cortical Bone Formation

Endocrinology ◽  
2003 ◽  
Vol 144 (5) ◽  
pp. 2132-2140 ◽  
Author(s):  
Keiichiro Kitahara ◽  
Muneaki Ishijima ◽  
Susan R. Rittling ◽  
Kunikazu Tsuji ◽  
Hisashi Kurosawa ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Formation ◽  
Bone Mass ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Wild Type ◽  
Mineral Density ◽  
Cortical Bone Mass ◽  
Intermittent Pth

Intermittent PTH treatment increases cancellous bone mass in osteoporosis patients; however, it reveals diverse effects on cortical bone mass. Underlying molecular mechanisms for anabolic PTH actions are largely unknown. Because PTH regulates expression of osteopontin (OPN) in osteoblasts, OPN could be one of the targets of PTH in bone. Therefore, we examined the role of OPN in the PTH actions in bone. Intermittent PTH treatment neither altered whole long-bone bone mineral density nor changed cortical bone mass in wild-type 129 mice, although it enhanced cancellous bone volume as reported previously. In contrast, OPN deficiency induced PTH enhancement of whole-bone bone mineral density as well as cortical bone mass. Strikingly, although PTH suppressed periosteal bone formation rate (BFR) and mineral apposition rate (MAR) in cortical bone in wild type, OPN deficiency induced PTH activation of periosteal BFR and MAR. In cancellous bone, OPN deficiency further enhanced PTH increase in BFR and MAR. Analysis on the cellular bases for these phenomena indicated that OPN deficiency augmented PTH enhancement in the increase in mineralized nodule formation in vitro. OPN deficiency did not alter the levels of PTH enhancement of the excretion of deoxypyridinoline in urine, the osteoclast number in vivo, and tartrate-resistant acid phosphatase-positive cell development in vitro. These observations indicated that OPN deficiency specifically induces PTH activation of periosteal bone formation in the cortical bone envelope.

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