Mechanical response of bovine articular cartilage under dynamic unconfined compression loading at physiological stress levels

The objective of the current study was to characterize the mechanical response of bovine articular cartilage under dynamic tensile loading. Testing was performed under an applied stress magnitude of 1.3 MPa and frequencies from 10−4 Hz to 10 Hz. The dynamic tensile modulus ranged from 20.1±7.0 MPa at 10−4 Hz to 64.0±9.7 MPa at 10 Hz. The phase angle derived from the area under the stress-strain hysteresis loop changed from 21.4±6.9° at 10−4 Hz to 1.1±0.2° at 10 Hz. Based on earlier theoretical predictions, the observed viscoelastic response in tension may be attributed to the intrinsic viscoelasticity of the collagen-proteoglycan matrix.

Download Full-text

Frictional Response of Bovine Articular Cartilage Under Creep Loading Following Proteoglycan Digestion With Chondroitinase ABC

Journal of Biomechanical Engineering ◽

10.1115/1.2133764 ◽

2005 ◽

Vol 128 (1) ◽

pp. 131-134 ◽

Cited By ~ 21

Author(s):

Ines M. Basalo ◽

Faye Hui Chen ◽

Clark T. Hung ◽

Gerard A. Ateshian

Keyword(s):

Articular Cartilage ◽

Friction Coefficient ◽

Treated Group ◽

Time Dependent ◽

Knee Joints ◽

Control Group ◽

Unconfined Compression ◽

Chondroitinase Abc ◽

Bovine Articular Cartilage ◽

Creep Loading

The specific aim of this study was to investigate the effect of chondroitinase ABC treatment on the frictional response of bovine articular cartilage against glass, under creep loading. The hypothesis is that chondroitinase ABC treatment increases the friction coefficient of bovine articular cartilage under creep. Articular cartilage samples (n=12) harvested from two bovine knee joints (1-3months old) were divided into a control group (intact specimens) and a treated group (chondroitinase ABC digestion), and tested in unconfined compression with simultaneous continuous sliding (±4mm at 1mm∕s) under a constant applied stress of 0.5MPa, for 2500s. The time-dependent response of the friction coefficient was measured. With increasing duration of loading, treated samples exhibited a significantly higher friction coefficient than control samples as assessed by the equilibrium value (treated: μeq=0.19±0.02; control: μeq=0.12±0.03; p=0.002), though the coefficient achieved immediately upon loading did not increase significantly (treated: μmin=0.0053±0.0025; control: μmin=0.037±0.0013; p=0.19). Our results demonstrate that removal of the cartilage glycosaminoglycans using chondroitinase ABC significantly increases the overall time-dependent friction coefficient of articular cartilage. These findings strengthen the motivation for developing chondroprotective strategies by increasing cartilage chondroitin sulfate content in osteoarthritic joints.

Download Full-text

Effect of Enzymatic Degeneration on the Frictonal Property of Articular Cartilage

Volume 1B: Extremity; Fluid Mechanics; Gait; Growth, Remodeling, and Repair; Heart Valves; Injury Biomechanics; Mechanotransduction and Sub-Cellular Biophysics; MultiScale Biotransport; Muscle, Tendon and Ligament; Musculoskeletal Devices; Multiscale Mechanics; Thermal Medicine; Ocular Biomechanics; Pediatric Hemodynamics; Pericellular Phenomena; Tissue Mechanics; Biotransport Design and Devices; Spine; Stent Device Hemodynamics; Vascular Solid Mechanics; Student Paper and Design Competitions ◽

10.1115/sbc2013-14461 ◽

2013 ◽

Author(s):

Shota Mochizuki ◽

Shun Yanagida ◽

Hiromichi Fujie

Keyword(s):

Articular Cartilage ◽

Collagen Fiber ◽

Unconfined Compression ◽

Cartilage Sample ◽

Bovine Articular Cartilage ◽

Frictional Properties ◽

Friction Tester ◽

Articular Cartilage Surface ◽

The Coefficient Of Friction ◽

Loaded Area

Articular cartilage is consisted of the chondrocyte, collagen fibers and proteoglycan, and interstitial fluid. Basalo et al reported that the coefficient of friction of bovine articular cartilage on a glass surface measured in unconfined compression fashion was increased by the degeneration of proteoglycan [1]. In their friction test, it was difficult to test a small cartilage sample having undulation while the loaded area in cartilage specimen was almost unchanged during friction. For the assessment of frictional properties of enzymatically degenerated cartilage in more physiological condition, we developed a friction tester that allows for performing friction tests of articular cartilage surface against a spherical indenter. With the tester, the loaded area in cartilage specimen translated along with frictional motion while the compressive stress exceeded more than 1 MPa. In the present study, the effect of enzymatic degeneration of proteoglycan and collagen fiber on property of articular cartilage using the friction tester.

Download Full-text