AN AGE-RELATED STUDY OF MORPHOLOGY AND CROSS-LINK COMPOSITION OF COLLAGEN FIBRILS IN THE DIGITAL FLEXOR TENDONS OF YOUNG THOROUGHBRED HORSES

The superficial digital flexor tendon is the most commonly injured ten don in the racing Thoroughbred, Despite the clinical significance of t his struct,re, only limited data exist regarding normal age-related mo rphology of the tensile units, the collagen fibrils, The age at which these collagen fibrils become mature in composition and structure may be of importance, Consequently, the association of age and collagen fi bril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds u p to and including three years of age has been studied, Replacement of immature crosslinks, peaking of the collagen fibril mass-average diam eter and collagen fibril index, and stabilization of collagen crimp mo rphology changes supported the hypothesis that both digital flexor ten dons become mature in structure by two years of age.