The Roles of Extensional and Shear Flows of Synovial Fluid and Replacement Systems in Joint Protection

Extensional flow oscillatory rheometry

“…It is notable that the extensional viscosity begins to fall beyond 500 s −1 strain rate. Similar results have been seen before in opposed jets experiments [37]. At this strain rate the Reynolds' number is approaching 0.5, so it is possibly due to inertial effects.…”

“…The rheological properties of synovial fluid, particularly in extension, are thought to be of vital importance in protecting the knee joint from sudden shock, e.g. from a high-load impact such as landing after a jump (Backus et al [37]). The shear viscosity is little changed from water (1.1 mPa s) whilst the extensional viscosity is in the range 3.3-15 mPa s [37].…”

“…from a high-load impact such as landing after a jump (Backus et al [37]). The shear viscosity is little changed from water (1.1 mPa s) whilst the extensional viscosity is in the range 3.3-15 mPa s [37]. Comparing the molecular response for aPS (Figs.…”

Osteoarthritic synovial fluid rheology and correlations with protein concentration

“…High molecular weight polymer molecules can produce dramatically different responses in extensional and shear flows ( Figure 1.3) [11]. Extensional strain can dissociate molecular entanglements of HA [74].…”

“…11 The dynamic rheological properties as a function of frequency for two OA SF samples before and after centrifugation. .…”