Control of bone architecture by functional load bearing

1992 ◽  
Vol 7 (S2) ◽  
pp. S369-S375 ◽  
Author(s):  
Lance E. Lanyon
Keyword(s):  
Bone Architecture ◽  
Load Bearing ◽  
Functional Load

A Reconciliation of Local and Global Models for Bone Remodeling Through Optimization Theory

1999 ◽  
Vol 122 (1) ◽  
pp. 72-76 ◽  
Author(s):  
G. Subbarayan ◽  
D. L. Bartel
Keyword(s):  
Optimization Theory ◽  
Optimality Criteria ◽  
Bone Architecture ◽  
Necessary Condition ◽  
Local Error ◽  
Mathematical Form ◽  
Global Models ◽  
Load Bearing ◽  
Global Criterion ◽  
The Cost

Remodeling rules with either a global or a local mathematical form have been proposed for load-bearing bones in the literature. In the local models, the bone architecture (shape, density) is related to the strains/energies sensed at any point in the bone, while in the global models, a criterion believed to be applicable to the whole bone is used. In the present paper, a local remodeling rule with a strain “error” form is derived as the necessary condition for the optimum of a global remodeling criterion, suggesting that many of the local error-driven remodeling rules may have corresponding global optimization-based criteria. The global criterion proposed in the present study is a trade-off between the cost of metabolic growth and use, mathematically represented by the mass, and the cost of failure, mathematically represented by the total strain energy. The proposed global criterion is shown to be related to the optimality criteria methods of structural optimization by the equivalence of the model solution and the fully stressed solution for statically determinate structures. In related work, the global criterion is applied to simulate the strength recovery in bones with screw holes left behind after removal of fracture fixation plates. The results predicted by the model are shown to be in good agreement with experimental results, leading to the conclusion that load-bearing bones are structures with optimal shape and property for their function. [S0148-0731(00)00601-4]

Damage of Articular Cartilage due to Mechanical Fatigue and Collagenase Action

2008 ◽  
Author(s):  
Ravi Namani ◽  
Narendra K. Simha ◽  
Jack L. Lewis
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Strong Evidence ◽  
Impact Loads ◽  
Enzymatic Cleavage ◽  
Load Bearing ◽  
Functional Load ◽  
Mechanical Fatigue ◽  
Fatigue Loads

Damage to the extracellular matrix (ECM) of articular cartilage is detrimental to its functional load-bearing properties. Cartilage ECM can be damaged chemically by enzymatic cleavage or mechanically either due to impact loads or long term fatigue loads at physiological levels. There is strong evidence that chronic long term loads in conjunction with chemical weakening can lead to osteoarthritic degeneration of cartilage [1, 2].

Prolonged Treatment of Ultra-Low Dose Chondroitinase ABC Improves Matrix Production in Engineered Cartilage

2013 ◽  
Author(s):  
Grace D. O’Connell ◽  
Victoria Cui ◽  
Robert J. Nims ◽  
Adam B. Nover ◽  
Gerard A. Ateshian ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Low Dose ◽  
Prolonged Treatment ◽  
Load Bearing ◽  
Functional Load ◽  
Diarthrodial Joints ◽  
Equilibrium Modulus ◽  
Matrix Production ◽  
Engineered Cartilage

Articular cartilage is the load bearing soft tissue of diarthrodial joints, and mechanical loading maintains the integrity of the tissue. The predominant extracellular matrix constituents, proteoglycans and collagen, allow cartilage to support the high compressive and tensile loads experienced in diurnal loading. Our laboratory has been successful in cultivating engineered cartilage constructs with a compressive equilibrium modulus and glycosaminglycan (GAG) content near native values [1, 2]. Many approaches to cultivating engineered cartilage have been limited by low collagen production in vitro, an impediment for attaining native functional load-bearing properties [3].

Load-Bearing in the Ovine Medial Tibial Condyle: Effect of Meniscectomy

1993 ◽  
Vol 06 (02) ◽  
pp. 100-104 ◽  
Author(s):  
D. M. Pickles ◽  
C. R. Bellenger
Keyword(s):  
Knee Joint ◽  
Contact Area ◽  
Mammalian Species ◽  
Total Removal ◽  
Load Bearing ◽  
Human Knee ◽  
Biochemical Effects ◽  
Pressure Sensitive ◽  
Medial Meniscectomy ◽  
Tibial Condyle

SummaryTotal removal of a knee joint meniscus is followed by osteoarthritis in many mammalian species. Altered load-bearing has been observed in the human knee following meniscectomy but less is known about biochemical effects of meniscectomy in other species. Using pressure sensitive paper in sheep knee (stifle) joints it was found that, for comparable loads, the load-bearing area on the medial tibial condyle was significantly reduced following medial meniscectomy. Also, for loads of between 50 N and 500 N applied to the whole joint, the slope of the regression of contact area against load was much smaller. Following medial meniscectomy, the ability to increase contact area as load increased was markedly reduced.The load bearing area on the medial tibial condyle was reduced following meniscectomy.

Effect of long-term loading on timber load-bearing elements

2015 ◽  
Vol 10 (2) ◽  
pp. 25-34
Author(s):  
Kristian Sogel
Keyword(s):  
Load Bearing

A THEORETICAL ITERATION FOR PREDICTING THE FEASIBILITY FOR IMMEDIATE FUNCTIONAL DENTAL IMPLANT LOADING

2020 ◽  
Author(s):  
Dennis Flanagan ◽  
Alessandro Fisher BS ◽  
Carmen Ciardiello ◽  
Vito Moreno ◽  
Alen Uvalic ◽  
...  
Keyword(s):  
Bone Density ◽  
Dental Implant ◽  
Cortical Thickness ◽  
Load Capacity ◽  
Functional Load ◽  
Implant Crown ◽  
Technical Issues ◽  
Implant Loading ◽  
Influential Parameters ◽  
Functional Loading

When planning an implant supported restoration the dentist is faced with the surgical and prosthetic technical issues as well as the patient’s expectations. Many patients wish an immediate solution to an edentulous condition. This is especially may be true in the esthetic zone. The extent of the zone is determined by the patient. The dentist may consider when it is feasible to load the supporting implants with definitive or provisional prosthetics. For the work herein, consideration of many parameters were theoretically assessed for inclusion: bone density, cortical thickness, seating torque, parafunction, bite load capacity, number of implants under load, implant/crown ratio, implant diameter and length. After assessment, the most influential parameters were selected. An iteration, using patient age, implant diameter, bite load capacity and cortical thickness, is now presented to aid the implant dentist in determining the feasibility for immediate functional loading of a just placed dental implant in a healed site. Extensive testing is required to develop this concept. According to this iteration, most immediate functional loaded implants would fail. A future refined and definitive formula may enable the clinician to safely immediately functional load an implant with a definitive prosthesis.

PARTICULAR QUALITIES OF CONSTRUCTION AND TECHNICAL EXPERTISE OF STRUCTURES AGRICULTURAL WAREHOUSE OF MINERAL FERTILIZERS

2020 ◽  
Author(s):  
I.O. Egorochkina ◽  
◽  
I.A. Serebryanaya ◽  
S. A. Jamaldinov ◽  
F.A. Bataeva ◽  
...  
Keyword(s):  
Functional State ◽  
Mineral Fertilizers ◽  
Technical Expertise ◽  
Technical Documentation ◽  
Load Bearing ◽  
Building Load

The article describes the features of construction and technical expertise of structures of agricultural warehouse of mineral fertilizers. A draft program for visual and detailed instrumental inspection of building load-bearing structures has been developed. In accordance with the recommendations of the regulatory and technical documentation, measures have been developed to repair and restore the functional state of damaged structures.

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