Image-based multiscale mechanical modeling shows the importance of structural heterogeneity in the human lumbar facet capsular ligament.

摘要: The lumbar facet capsular ligament (FCL) primarily consists of aligned type I collagen fibers that are mainly oriented across the joint. aim this study was to characterize and incorporate in-plane local fiber structure into a multiscale finite element model predict mechanical response FCL during in vitro tests, accounting for heterogeneity different scales. Characterization accomplished by using entire-domain polarization-sensitive optical coherence tomography measure cadaveric FCLs ( $$n=6$$ ). Our imaging results showed have highly heterogeneous distribution neither isotropic nor completely aligned. averaged orientation $$+9.3^{\circ }$$ $$+29.9^{\circ inferior region $$+5.1^{\circ middle superior regions), with respect lateral–medial direction (superior–medial inferior–lateral). These data were used construct structural models, which then experimental gross force–strain behavior strain equibiaxial strip biaxial tests. For loading, fit well but underestimated forces $$\sim $$ 16% on average. We also observed pronounced field, stretch ratios elements along axis sample typically ranging from about 0.95 1.25 12% direction. This work highlights FCL, is significant both terms injury prediction microstructural constituents’ (e.g., neurons) behavior.