Charakterisierung der Schädigungsmechanismen einer equinen oberflächlichen Beugesehne zur gezielten Behandlung von läsionierten Arealen unter Anwendung eines morphofunktionell und biomechanisch bewerteten Fasergerüstes

A damage to the superficial digital flexor tendon (SDFT) on the anterior extremities of the horse often leads to an out-of-service position, which in serious cases results in an euthanasia of the animal. The aim of this work is to evaluate the suitability of an implanted decellularized replacement tissue for the treatment of a topical lesion section in addition to the investigation of the damage mechanisms of an initially intact equine SDFT.
After fatigue loading, the onset of damage is indicated by inhomogeneities of the matrix,in the form of interfibre space widening and discontinuities within the collagen structure, up to complete rupture in the middle metacarpal region. A larger crimp angle in the peripheral area leads to a larger toe strain, which in turn results in an early loading of the central fibres. In addition to the purely structural factors, biochemical deformation effects were registered. A higher proportion of fibrils, which is decisive for the strength of the tendon, measured in the entire tissue construct, ensures a higher modulus of elasticity in the central area, which additionally leads to a higher load in this zone with a identical strain of the peripheral fibres.
In order to avoid an inferior scar tissue in the lesioned tendon section,the decellularized donor tissue is suitable as an implanted substitute structure up to a defined load. On the basis of existing in vivo studies during the convalescence, only a low-loading step movement of the horse, combined with a suitable ground, can be recommended as to prevent a renewed rupture in the treatment period. Treatment of the ruptured tendon section with a suitable suture technique will continue to be necessary for the fixation of the collagen structure. Rather, the decellularized implant as a filling material could positively influence the healing process. A sufficient strength of the implant structure above the permissible load-bearing capacity of the suture connection can be demonstrated by means of this work‘s findings.