INVESTIGADORES
ABRAHAM Gustavo Abel
congresos y reuniones científicas
Título:
Mechanical testing of injectable self-curing polyurethane formulations for nucleus pulposus replacement
Autor/es:
G.A. ABRAHAM; L. SACCHETTI; F. BUFFA; P.M. FRONTINI
Lugar:
Kerkrade, The Netherlands
Reunión:
Conferencia; 14th International Conference on Deformation, Yield and Fracture of Polymers, DYFP2009; 2009
Institución organizadora:
Eindhoven University of Technology
Resumen:
Lower back pain is one of the most common medical problems in the world,
mainly produced as a result of degenerative disc disease. Currently,
the replacement of the nucleus pulposus with an in situ formed
biomaterial is a promising non-fusion technology that involves
minimally invasive surgical techniques. This work focuses on the
mechanical properties of self-curing crosslinked polyurethane foams. The
stress-strain performance of cell-closed foam samples prepared by using
the same procedure followed in the surgical practice was investigated
through unconfined uniaxial and confined compression tests. The
compressive elastic moduli were in the range of 1.7-4.7 MPa, being in
the interval proposed for a solid implant to prevent inward bulging of
the annulus fibrous. The Poissons ratio was determined by
videoextensometry. The values were not significantly different from
those obtained for the native nucleus. A very small hysteresis (2%) was
observed even after 100 cyclic loadings to 25% strain. Stress softening
and residual strain were not found. Stress relaxation experiments
displayed the good elastic recovery. The mechanical behavior under
confined compression tests showed interesting features. Samples
exhibited two regions of behaviour at strains less that 0.25, an
approximate linear region followed by a densification region starting at
strains about 0.2. Stress softening and residual strain after 100
cycles were not found either. However, samples exhibited considerable
hysteresis (20 %) under rigid confinement without undergoing any
macroscopic failure. The initial dimensions were completely recovered
after unloading. These preliminary results suggest that this novel
implant may prove to be a suitable nucleus pulposus substitute.