FAB - Week 2 (Part 1) - Bone and Cartilage biomechanics

Vocabulary flashcards covering bone and cartilage biomechanics, including structure, composition, loading modes, and effects of exercise and aging.

Cortical Bone

High-density bone with low porosity, typically around 2 g/cm3 density and 5-30% porosity. Contains Haversian systems.

Cancellous Bone

Spongy bone with lower density and high porosity, around 0.1-1.4 g/cm3 density and 30-90% porosity. Lacks Haversian systems.

Stress

Force per cross-sectional area (CSA) acting on a material.

Strain

Change in length divided by original length, often expressed as a percentage.

Young's Modulus

Slope of the stress-strain curve, representing stiffness of the material.

Orthotropic

Material with one axis of symmetry in its material properties (e.g., femur).

Viscoelasticity

Property of a material exhibiting both viscous (fluid) and elastic (solid) characteristics.

Hysteresis

Energy loss due to internal friction in a viscoelastic material during loading and unloading.

Load Relaxation

Decrease in load over time under constant length or deformation.

Creep

Increase in length over time under constant load.

Fatigue Failure

Fracture resulting from repetitive loading below the material's ultimate strength.

Wolf's Law

Bone is laid down in areas of high stress and reabsorbed in areas of low stress.

Articular Cartilage (AC)

Cartilage found at articulating bone ends of diarthrodial joints, facilitating smooth joint rotations and reducing friction.

Chondrocytes

Cells within articular cartilage that produce, organize, and maintain the extracellular matrix (ECM).

Extracellular Matrix (ECM)

Predominantly collagen (type II), proteoglycans, and water; determines the mechanical properties of articular cartilage.

Proteoglycans (PGs)

Molecules in articular cartilage ECM, such as aggrecans, that contribute to the tissue's compressive resistance.

Glycosaminoglycans (GAGs)

Negatively charged components of proteoglycans that resist compression through charge repulsion.

Load Relaxation (Cartilage)

Gradual reduction in tissue stress under constant loading due to fluid exudation and internal fluid movement in cartilage.

Osteoarthritis (OA)

Joint disorder characterized by cartilage softening, fibrillation, fissuring, and loss, potentially leading to bone exposure.