Stoltz et al. addresses the over-four-decade controversy in synovial joint tribology as to what happens as two cartilage surfaces approach contact 1. Is the fluid in the interarticular space forced into the cartilage layers in “boosted” lubrication ala Dowson et al. 2 or is it expressed from the cartilage layers in “weeping” lubrication ala McCutchen 3?

The Soltz et al. study, which supports the Dowson “boosted” hypothesis is totally theoretical, as is the Dowson hypothesis with no experimental confirmation of which I am aware. In Soltz et al. a mathematically-modeled, flat, smooth, two-dimensional “cartilage layer” is approached and penetrated by a model of a 2-D, “rippled, rigid indenter” purported to represent the complex surface of natural cartilage.

The authors group their reference 2, Macirowski et al. 4 with 3 other references and characterize Macirowski et al. (along with the other 3 references) as “a contact simulation between smooth...

1.
Mann
,
R. W.
,
1998
, “
Discussion
,”
J. Tribology
,
120
, pp.
249
251
.
2.
Walker
,
P. S.
,
Dowson
,
D.
,
Longfield
,
M. D.
, and
Wright
,
V.
,
1968
, “
Boosted Lubrication in Synovial Joints by Fluid Entrapment and Enrichment
,”
Ann. Rheum. Dis.
,
27
, pp.
512
560
.
3.
McCutchen
,
C. W.
,
1959
, “
Mechanism of Animal Joints: Sponge-Hydrostatic and Weeping Bearings
,”
Nature (London)
,
184
, pp.
1284
1285
.
4.
Macirowski
,
T.
,
Tepic
,
S.
, and
Mann
,
R. W.
,
1994
, “
Cartilage Stresses in the Human Hip Joint
,”
J. Biomech. Eng.
,
16
, pp.
10
18
.
5.
Rushfeldt
,
P. D.
,
Mann
,
R. W.
, and
Harris
,
W. H.
,
1981
, “
Improved Techniques for Measuring In Vitro the Geometry and Pressure Distribution in the Human Acetabulum—I. Ultrasonic Measurement of Acetabular Surfaces, Sphericity and Cartilage Thickness
,”
J. Biomech.
,
14
, pp.
253
260
.
6.
Tepic
,
S.
,
Macirowski
,
T.
, and
Mann
,
R. W.
,
1983
, “
Articular Cartilage Mechanical Properties Elucidated by Osmotic Loading and Ultrasound
,”
Proc. Natl. Acad. Sci. U.S.A.
,
80
, pp.
3331
3333
.
7.
Rushfeldt, P. D., Mann, R. W., and Harris, W. H., “Improved Techniques for Measuring In Vitro the Geometry and Pressure Distribution in the Human Acetabulum—II Instrumented Endoprosthesis Measurement of Articular Cartilage Surface Pressure Distribution,” J. Biomech., 19, pp. 315–323.
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