Project details


How does mechanical damage in cartilage starts?

cartilage joint Damage

dr. P.K. Sharma
H.C. van der Veen

Type of project:
Pilot project (year 2 or 3), Stage Wetenschap / Researchproject of MD/PhD programme

Nature of the research:

Fields of study:
biomaterials orthopedics

Background / introduction
Hyaline cartilage defects and osteoarthritis both involve enzymatic degradation and mechanical damage through cracking
Research question / problem definition
What are the impact loads at which cartilage cracks initiate? How does the crack propagate? Does enzymatic degradation of collagen or proteoglycans affect the crack initiation and propagation?
: Bovine cartilage taken from 2 year old bull knees will be used for all the experiments. Osteochondral condyles will be placed against each other in contact and the falling ball will impose the impact load at the cartilage-cartilage interface as shown in the figure. By tweaking the placement of the condyles purely normal stresses can be imposed or a combination of normal and shear stresses. The aim is to find a reproducible value of a threshold impact energy in normal and shear condition at which cartilage crack initiates. Optical coherence tomography and Indian ink methods will be used to identify the cracks and its length. Pre-scale films (From Fuji films) will be placed at the cartilage-cartilage interface to identify the cross-sectional area of contact. Ball of different weights will be dropped from different heights to achieve different levels of kinetic energy which will be imposed on the cartilage. If time permits in the research then the condyles will be first exposed to collagenase III or chondroitinase ABC to degrade collagen type II and proteoglycans respectively and the thresholds determined.
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Santos S., Emery N., Neu C.P.,et al. Propagation of microcracks in collagen networks of cartilage under mechanical loads[J]. Osteoarthritis Cartilage, 2019, 27(9): 1392-1402.
Tomatsu T., Imai N., Takeuchi N.,et al. Experimentally produced fractures of articular cartilage and bone. The effects of shear forces on the pig knee[J]. The Journal of bone and joint surgery British volume, 1992, 74(3): 457-462.
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