The Journal of Bone and Joint Surgery, Vol 57, Issue 4 527-534, Copyright © 1975 by Journal of Bone and Joint Surgery, Inc
In vitro wear of articular cartilage
H Lipshitz, R Etheredge and MJ Glimcher
Seeking a reliable chemical index of the wear of articular cartilage during
in vitro experiments, the contents of hydroxyproline, hexosamine, and the
amino acid composition of adult bovine articular cartilage were determined
as functions of depth from the surface. The hydroxyproline content,
expressed as per cent of dry weight of tissue, was constant throughout the
thickness of the tissue except in a surface region approximately
twenty-five micrometers thick; the hexosamine content in this region was
less than in the interior of the tissue; the collagen content was higher
and the amino acid composition was less like that of pure collagen here
than in the interior, indicating that the content of noncollagenous protein
in the superficial layer of cartilage was greater than that in the
interior. It was also evident that adult bovine articular cartilage
contains significant amounts of collagen with a low hydroxylysine content,
presumably Type I as well as Type II. Since the content of hydroxyproline
is constant throughout the cartilage and the collagen and proteoglycan
constituents of the intact tissue are relatively insoluble, the
hydroxyproline content of the lubricant and the wear debris can be used to
measure the extent of wear of articular cartilage during in vitro
experiments. However, approximately 10 per cent of the hydroxyproline and
50 to 60 per cent of the glycosaminoglycans of the wear debris are
dissolved in the lubricating fluid. Therefore, both the lubricant (solvent)
and the solid wear debris must be analyzed to determine the amount of
cartilage wear.
CiteULike 
Connotea 
Del.icio.us 
Technorati What's this?
