Numerical investigation of reflections of fast and slow longitudinal waves at a boundary between cancellous bone and cortical bone

2012 ◽  
Author(s):  
A. Hosokawa
Keyword(s):  
Cortical Bone ◽  
Numerical Investigation ◽  
Cancellous Bone ◽  
Longitudinal Waves

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.

scholarly journals Prediction Modeling and Sensitivity Analysis of Robot Bone Milling Temperature Operated by a Doctor

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Heqiang Tian ◽  
Jingbo Pan ◽  
Yu Gao ◽  
Xiaoqing Dang ◽  
Bin Tian ◽  
...  
Keyword(s):  
Prediction Model ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Bone Cells ◽  
Prediction Method ◽  
Milling Process ◽  
Milling Parameters ◽  
Cutting Surface ◽  
Milling Temperature ◽  
Cutting Modes

Bone milling is a common method in robot orthopedic surgery. However, excessive milling temperature will cause thermal necrosis of bone cells and tissues. It is necessary to carry out further research and analysis on the robot bone milling process considering the lamina milling skills of spinal surgeons and clinical practice to reduce the damage to bone cells and nearby tissues and obtain good cutting surface quality. Considering the randomness of milling parameters during operation, a prediction method of milling temperature model for ball milling cutter considering the doctor’s surgical skills was proposed based on response surface method. Because of material anisotropy and microstructure difference between the cortical bone and cancellous bone, this paper would analyze the influencing factors in different bone layers to establish the prediction model of milling temperature in the segments of cortical bone and cancellous bone. Also, the influence and distribution of milling parameters on temperature in three cutting modes such as parallel cutting mode, cross cutting mode, and vertical cutting mode in the cortical bone region were analyzed. The parameter sensitivity of the milling temperature prediction model was analyzed by the Sobol method, and the influence of the input parameters on the output milling temperature was analyzed quantitatively.

scholarly journals Propagation of two longitudinal waves in a cancellous bone with the closed pore boundary

2011 ◽  
Vol 130 (2) ◽  
pp. EL122-EL127 ◽  
Author(s):  
Katsunori Mizuno ◽  
Yoshiki Nagatani ◽  
Keisuke Yamashita ◽  
Mami Matsukawa
Keyword(s):  
Cancellous Bone ◽  
Longitudinal Waves ◽  
Closed Pore
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