Biomedical Engineering Reference
In-Depth Information
Figure 1.7:
Mechanotransduction can occur via pulling, compressing, and shearing the cells (bold ar-
rows). Other stimuli can include streaming potentials (fine arrows).
Chondrocytes, the metabolic unit of cartilage, reside in lacunae, which has high collagen
type VI contents.
The lamina splendens, consisting of collagen fibers oriented along the direction of stress, covers
the cartilage surface and serves to both resist shear and entrap the ECM within the tissue.
The force exerted on the hip has been calculated to be 3.3 times a person's bodyweight.The knee
experiences a load of approximately 3.5 times bodyweight, the ankle 2.5 times bodyweight,
and the shoulder 1.5 times bodyweight.
The compressive aggregate modulus,
H
A
, of cartilage ranges from 0.08 to 2 MPa and varies
by depth in the tissue, location on the joint, and species. On average, the aggregate modulus
is around 800 kPa.
The tensile modulus of healthy human cartilage varies from 5 to 25 MPa. Thus, it should
be remembered that the tensile modulus is about one order of magnitude higher than the
compressive modulus.
