Comment on "Hydrostatic pressurization and depletion of trapped lubricant pool during creep contact of a rippled indenter against a biphasic articular cartilage layer".

In the Conclusion section of the above article its authors wrote, ‘‘ . . . contrary to the weeping hypothesis, however, the current analysis demonstrates that @after load is applied# lubricant fluid trapped between a rigid impermeable surface and a porouspermeable cartilage layer flows monotonically into the cartilage during contact creep; no fluid flow from the cartilage into the lubricant pool is observed . . . . @T#his result is in better agreement with the premise of the boosted lubrication theory of Walker et al. @1#’’ The article gives the duration of ‘‘contact creep’’ as .4 seconds for roughness similar to that of cartilage @2# and about 10 seconds for roughness 5 times as tall and 10 times longer in wavelength.