Gaining Insight into the Deformation of Achilles Tendon Entheses in Mice. Issue 11 (26th July 2021)

• Record Type: Journal Article
• Authors: Sartori, Julian; Köhring, Sebastian; Bruns, Stefan; Moosmann, Julian; Hammel, Jörg U.
• Other Names: Müller Martin guestEditor.; Busch Sebastian guestEditor.; Krywka Christina guestEditor.; Moulin Jean-Francois guestEditor.; Pyczak Florian guestEditor.; Staron Peter guestEditor.; Thiry Marc guestEditor.
• Is Part Of: Advanced engineering materials. Volume 23:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-26
• Subjects: digital volume correlation -- hard–soft transition -- multiscale tendon mechanics -- propagation-based phase contrast -- soft tissue imaging -- synchrotron radiation-based microcomputed tomography; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.202100085
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Understanding the biomechanics of tendon entheses is fundamental for surgical repair and tissue engineering but also relevant in biomimetics and paleontology. Examinations into the 3D tissue deformation under load are an important element in this process. However, entheses are difficult objects for microcomputed tomography due to extreme differences in X–ray attenuation. Herein, the ex vivo examination of Achilles tendon entheses from mice using a combination of tensile tests and synchrotron radiation‐based microcomputed tomography is reported. Strains and volume changes are compared between the more proximal free tendon and the distal tendon that wraps around the Tuber calcanei . Tomographic datasets of relaxed and deformed entheses are recorded with propagation‐based phase contrast. The tissue structure is rendered in sufficient detail to enable manual tracking of patterns along the tendon, as well as digital volume correlation in a suitable pair of tomographic datasets. The strains are higher in the distal than in the proximal tendon. These results support the existence of a compliant zone near the insertion. Necessary steps to extend the automatic tracking of tissue displacements to all stages of the deformation experiment are discussed. Abstract : Herein, the method and the results of the first tomographic deformation study of intact tendon‐bone insertions at microscopic resolutions are presented. The method is evaluated in detail. Under load, higher strains are found to occur in the distal tendon near the insertion than in the more proximal free tendon. Thereby, previous findings from dissected tendon‐bone insertions are confirmed.