THE EFFECT OF DIABETES ON THE VISCOELASTIC PROPERTIES OF RAT KNEE LIGAMENTS

A series of experiments was performed to determine the effect of diabe tes on the viscoelastic properties of knee joint ligaments. The experi mental model was collateral ligaments from spontaneously diabetic, hyp erglycemic (BBZDP/Wor) mts, and various controls including nondiabetic littermates, insulin treated diabetic rats, and alloxan treated rats. Material properties were measured using a dynamic, uniaxial lending p aradigm. Ligaments were subjected to load controlled, sinusoidal tensi le testing, using frequencies from 0.1 to 2.0 Hz. The resulting data w ere used to determine the storage and loss compliances of the ligament s. Storage compliance, which reflects tissue elastic properties, did n ot differ between groups. Loss compliance, which reflects the viscous component of the tissue response, was increased in the hyperglycemic a nimals. Thus, hyperglycemic diabetes affects tissue mechanical propert ies through the viscous rather than the elastic component of the respo nse to dynamic loading. Rats treated with alloxan to induce diabetes d id not show an increase in loss compliance.