The mechanical properties of fresh versus fresh/frozen and preserved (Thiel and Formalin) long head of biceps tendons: A cadaveric investigation

Abstract

Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n=7) with fresh-frozen (n=8), formalin embalmed (n=15), and Thiel-preserved (n=6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12N/mm in the fresh group, increasing to 40.1N/mm in the fresh-frozen group, 50.3N/mm in the formalin group, and 52N/mm in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6MPa), to fresh-frozen (55.3MPa), to Thiel (82.5MPa), with the stiffest being formalin (510.6MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Young's modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.

Comparison of the histological structure of the tibial nerve and its terminal branches in the fresh and fresh-frozen cadavers

“…While literature provides comparative analysis of the fresh and fresh-frozen tendons [18,6], bones [10,26,41], osteochondral allografts [29] there is lack of such comparison for the human peripheral nerves. Hohmann et al [18] revealed that the long head of biceps tendons showed higher loads to failure and lower elasticity in the fresh-frozen samples when compared to the fresh specimens. At the same time fresh tendons were wider and presented larger CSA.…”

Anatomic evaluation of the insertional footprints of the iliofemoral and ischiofemoral ligaments: a cadaveric study

“…In this study, all assessments were performed using fresh frozen cadaver specimens. A fresh frozen cadaver is currently the closest model to reality and has advantages in terms of the quality of soft tissue, including minimal tissue changes with realistic hardness, colour, and pliability (Table 3) [18,19]. Therefore, we considered the fresh frozen cadaver to be the most suitable model for our study.…”

Dynamic mechanical characterization and viscoelastic modeling of bovine brain tissue

“…Human brain tissue was previously reported with stiffer mechanical properties than porcine brain tissue [65], while the similar dynamic moduli of human and porcine brain tissue were found through dynamic shear tests [8] and the dynamic mechanical behaviors in different animal brain tissues were measured to be close [66]. From the literature, the fresh human tissue exhibited relatively softer mechanical properties than the human autopsy results [67] which implied the animal brain tissue may generate closer data. Further, the anatomical structure between animal and human brains has been analogous.…”