Clinical application of titanium nickelide knitwear based on the quantitative assessment of rheological similarity to soft biological tissues

Abstract

Samples of metal knitted mesh made of the 40 μm, 60 μm and 90 μm diameter TiNi wires are studied by uniaxial tension to rupture and uniaxial cyclic tension. It was found that the metal knitted TiNi mesh behaves like a hyperelastic material under uniaxial tension in contrast to the superelastic wire from which it is made. Using the rheological models of Gent, Neo-Hookean, Mooney–Rivlin and Bergstrom-Boyce, the calculation of the cyclic tension of the knitted mesh was carried out. The similarity of the mechanical behavior of knitted mesh and biological tissues is shown. Criteria for quantitative assessment of the biomechanical compatibility of a knitted mesh implant for plasty of hyperelastic biological tissues are proposed.The main criteria for the rheological similarity of knitted mesh and soft tissues are the ultimate tensile strength, elastic modulus and the range of low-modulus and high-modulus elastic strain under loading and unloading; the residual strain value during cyclic tension.It has been found that knitted mesh made of superelastic TiNi wire exhibits a rubber-like behavior characteristic of hyperelastic materials under soft zero cyclic tension. At the same time, in the most loaded contact areas of the superelastic TiNi wire, the martensitic transition did not affect the tension cycles is due to friction, which counteracts the recovery of elastic strain during unloading. It has been established that the Bergstrom–Boyce model is closest in terms of the stress–strain diagram to the knitted mesh and biological tissues. Knitted mesh implants made of nickeide titanium wire were used for plasty of soft tissues and musculoskeletal complexes. The developed method for quantitative assessment diagram of the hyperelastic knittes mesh. The residual strain during the first two tension of the biocompatibility of the implant and biological tissue make it possible to choosу knitteв mesh with a certain wire diametre, focusing on the forces developed by the knitted mesh and the variable elasticity modulus. The knitted mesh was applied without additional fixation, using elastic self-fixation of knitted mesh loops into soft tissues.