Biomechanical Properties of Normal Tendons, Normal Palmar Aponeuroses and Palmar Aponeuroses from Patients with Dupuytren's Disease Subjected to Elastase and Chondroitinase Treatment

Abstract

Normal tendons, normal palmar aponeuroses and specimens from patients with Dupuytren's disease, namely apparently normal palmar aponeuroses and contracture bands were subjected to elastase and chondroitinase ABC digestion. Maximum Young's modulus, normalized hysteresis loop and residual elongation were determined before and after enzyme treatment. In normal tendons, normal and apparently normal palmar aponeuroses both normalized hysteresis loop and residual elongation increased significantly after elastase treatment, whereas the stiffness decreased. Normalized hysteresis loop and residual elongation display changes corresponding to the amount of digested elastin. The increased viscosity of untreated contracture bands containing less elastin, as compared to normal palmar aponeurosis, was not affected by elastase. Obviously, the elastic fibers in normal shape and distribution are responsible for maintaining an elastic status with a low viscous stress component. With the exception of contracture bands chondroitinase ABC caused a minor increase of residual elongation and as opposed to elastase a decrease of normalized hysteresis loop indicating an increased mobility of the tissue fibers.

Evidence against proteoglycan mediated collagen fibril load transmission and dynamic viscoelasticity in tendon

“…Thus, our results tend to disprove the theory that DS and CS side-chains of SLRPs mechanically interconnect discontinuous adjacent collagen fibrils and that they maintain the tissue integrity of tendons during tensile loading. While this hypothesis has been postulated and supported by semi-quantitative observational evidence (Cribb and Scott, 1995;Liao and Vesely, 2007;Redaelli et al, 2003), a number of other studies in both tendon (Millesi et al, 1995;Rigozzi et al, 2009;Robinson et al, 2005;Screen et al, 2006), and ligament (Lujan et al, 2007a) lend support to our contrary findings.…”

“…This viscoelastic behavior has been directly associated with tissue water content (Chimich et al, 1992;Haut and Haut, 1997;Lam et al, 1993;Mijailovich et al, 1994;Woo et al, 1993) and the highly hydrophilic tendon PGs have been hypothesized to regulate tissue hydration and viscoelastic frictional losses associated with fluid flow through the solid matrix (Elliott et al, 2003;Haut, 1985;Screen et al, 2006). Again, available experimental evidence yields a convoluted picture, with support from experiments showing that enzymatic disruption of PGs side-chains reduces viscoelastic effects in tendon and palmer aponeuroses (Millesi et al, 1995) and that tendons from decorin knock-out mice show reduced strain-rate sensitivity (Robinson et al, 2004), but with other experiments indicating increased rates of stress relaxation in the same mice (Elliott et al, 2003).…”

“…There is some evidence that sulfated GAGs play a role in quasi-static tendon mechanics (Cribb and Scott, 1995;Liao and Vesely, 2007;Redaelli et al, 2003), while other studies indicate that this may not be true (Lujan et al, 2007a;Millesi et al, 1995;Rigozzi et al, 2009). Some researchers have proposed that GAGs might rather influence dynamic viscoelastic tissue properties (Elliott et al, 2003;Lujan et al, 2007a;Robinson et al, 2004;Screen et al, 2005), but this also remains to be conclusively established.…”

“…Using a widely employed and highlyreproducible animal model for investigating tendon mechanics, GAG side-chains in rat tail tendon fascicles (RTTF) were selectively digested using a buffered chondroitinase ABC solution (Millesi et al, 1995;Prabhakar et al, 2005). Water content of tested tissues was carefully regulated to approximate a physiological state, and to avoid artifacts induced by the GAG digestion protocol.…”

Comparison of the Effect of Different Inhibitors on the Non-Enzymatic Glycation of Rat Tail Tendons and Bovine Serum Albumin

“…Tensile tests and thermal contraction experiments A tensile testing device was used 14 consisting of the following main components; a spindle driven by a gear box motor, a load cell with a maximum load of 20 N and a resolution of 10mN, a potentiometer, the specimen clamps to which abrasive paper (400 grit) was glued, and a bath containing PBS. The temperature of the bath was controlled by a microprocessor-based thermostat (programmer/controller PS-962, Rikadenki).…”