Fig. 11.

The labrum, stiff under tension, acts as a seal. The joint space, thus, contains a 0.4-mm layer of pressurized fluid, which protects the articular surfaces. Contact is resisted by the high fluid pressures and the tight labral ring (black arrow), where the peak strain can reach 2 %. This pressurizes the interstitial fluid within the cartilage. This pressurization resists “consolidation” or the forcing of fluid out of the cartilage (reproduced with permission from Ferguson et al. [18], Fig. 1)