Search Results - (Author, Cooperation:K. A. Athanasiou)

2012-11-20

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Biomechanical Phenomena ; Bone Regeneration ; Bone and Bones/physiology ; Cartilage, Articular/*physiology ; Humans ; Mesenchymal Stromal Cells/physiology ; Osteoblasts/physiology ; Osteoclasts/physiology ; *Regeneration ; Tissue Engineering/*methods ; *Tissue Scaffolds

1573-9686

Tibiotalar joint ; Articular cartilage ; Material properties ; Creep indentation ; KLM biphasic theory

Springer Online Journal Archives 1860-2000

Medicine

Technology

Abstract The material properties of normal cadaveric human cartilage in the ankle mortice (tibiotalar articulation) were evaluated to determine a possible etiologic mechanism of cartilage injury of the ankle when an obvious traumatic episode is not present. Using an automated indentation apparatus and the biphasic creep indentation methodology, creep indentation experiments were performed in five sites in the distal tibia, one site in the distal fibula, and eight sites in the proximal talus of 14 human ankles (seven pairs). Results showed significant differences in the mechanical properties of specific human ankle cartilage regions. Topographically, tibial cartilage is stiffer (1. 19 MPa) than talar cartilage (1.06 MPa). Cartilage in the anterior medial portion of the tibia has the largest aggregate modulus (H A =1.34 MPa), whereas the softest tissue was found to be in the posterior lateral (0.92 MPa) and the posterior medial (0.92 MPa) regions of the talus. The posterior lateral ridge of the talus was the thickest (1.45 mm) and the distal fibula was the thinnest (0.95 mm) articular cartilage. The largest Poisson's ratio was found in the distal fibula (0.08). The lowest and highest permeability were found in the anterior lateral regions of the astragalus (0.80 × 10−15 m4N−1sec−1) and the posterior medial region of the tibia (1.79 × 10−15 m4N−1sec−1), respectively. The anterior and posterior regions of the lateral and medial sites of the tibia were found to be 18–37% stiffer than the anatomically corresponding sites in the talus. The biomechanical results may explain clinically observed talar dome osteochondral lesions when no obvious traumatic event is present. Cartilage lesions in a repetitive overuse process in the ankle joint may be related to a disparity of mechanical properties between the articulating surfaces of the tibial and talar regions.

Electronic Resource

1573-9686

Articular cartilage biomechanics ; Rat cartilage ; Diet ; Aging ; Creep indentation ; Mechanical properties

Springer Online Journal Archives 1860-2000

Medicine

Technology

Abstract The objectives of this study were to investigate the effects of aging and diet restriction on the biomechanical properties of articular cartilage, using a well-controlled rat model (Fischer 344). This animal model is recommended by the National Institute of Aging specifically to study aging and diet issues. The intrinsic biomechanical properties of articular cartilage were obtained using a creep indentation approach. The ages chosen (6, 12, 18, 24 months of age) correspond to approximate human ages of 20 to 80 years old. The diet regimen employed in this study used either an ad libitum fed group or a group fed 60% of the mean food intake of the ad libitum group. The results demonstrate that, unlike bone, rat articular cartilage biomechanical properties are not affected in a discernible manner by diet restriction, despite the fact that diet-restricted animals were significantly lighter in terms of body weight. Age effects on biomechanical properties are found only at 6 and 12 months probably due to developmental reasons, but not at later ages. It appears that aging and diet restriction have profoundly different effects on articular cartilage and bone. Another significant result of this study was to establish the rat as a suitable animal model to study cartilage biomechanical properties. Thus, the rat can be added to the list of animals that can be used to study structure-function and pathophysiological relationships in articular cartilage. © 2000 Biomedical Engineering Society. PAC00: 8714Ee, 8715La, 8719Rr

Electronic Resource