PMC

Dependence of (A) kinetic (μ_kinetic) and (B) static (μ_static) friction coefficients on the MW (kDa) and concentration (mg/ml) of HA. n = 6; data are mean ± SEM.

Effect of joint injury on the boundary lubrication of articular cartilage by eSF. (A) Kinetic friction coefficients and (B) static friction coefficients plotted on a semi-log scale for NL-eSF (n = 20), AI-eSF (n = 10) and CI-eSF (n = 10). Data are mean ± SEM, and differing letters indicate significant differences between groups at p<0.05.

Dependence of (A) kinetic (μ_kinetic) friction and (B) static (μ_static) friction (at T_ps = 120s) of NL- and AI-eSF before and after the addition of exogenous HA (+HA) of average MW 800 or 4,000 kDa. n = 3 – 9; Data are mean ± SEM, n = 3 – 9, and differing letters indicate significant differences between groups at p<0.05 or p<0.001.

Effect of joint injury on PRG4 (A, B) and SAPL (C, D) in NL-eSF (n=19–20), AI-eSF (n=10), and CI-eSF (n=10) (A) Representative PRG4 Western blot probed with an antibody to Lubricin/PRG4; (B, D) concentrations of PRG4 (μg/ml) and SAPL (mg/ml), respectively; and (C) spectrophotometric absorption profiles for the reaction products of SAPL from pooled NL-eSF, CI-eSF, and AI-eSF. Data are mean ± SEM, and differing letters indicate significant differences between groups at p<0.05 or p<0.001.

Effect of joint injury on hyaluronan (HA) (A) concentration (mg/ml) and (B, C) HA molecular weight (MW) distribution in NL-eSF (n = 19–20), AI-eSF (n = 10) and CI-eSF (n = 10). (B) Electrophoretic separation of typical samples. (C) Concentration of HA in 0.05 – 0.25, 0.25 – 0.5, 0.5 – 1, 1 – 2.5, and 2.5 – 7 MDa ranges. Data are mean ± SEM, and differing letters indicate significant differences between groups at p<0.05.

Arthroscopic views of a normal (A) and acutely (B) injured metacarpophalangeal joint with a fracture fragment (indicated by the solid arrow head) off the proximal dorsal aspect of the first phalanx (P) with synovium (S) and distal metacarpus (Mc) also shown; (C) normal and (D) chronic injury of the equine antebrachiocarpal joint with a fragment off the intermediate (I) carpal bone and full-thickness erosion of the articular cartilage, as well as chronic synovitis (thickened synovial villi indicated by narrow arrow head).