Vincula tendinum of human hands with special reference to vascular patency.

As persisting parts of the mesotendon, Vinculum breve and Vinculum longum are known to serve as transport and conduction pathways to the intravaginal segments of flexor tendons. For morphological evaluation of their constancy, they were dissected out of, measured, and histologically examined on the 2nd-5th fingers in 53 hands of donated cadavers. The Vincula brevia existed in all cases more or less in association with the insertion of the superficialis as well as profundus flexor tendon, meanwhile the Vincula longa varied in number from 0 to 3 per tendon from one finger to the others, even 4 in the case of the index superficialis tendon. Light microscopic investigation of vascular patency was carried out on semithin resin sections of 137 Vincula longa obtained from the flexor superficialis and profundus tendons of 53 index fingers. Up to 5 or more arterial and venous vessels were counted per Vinculum longum. The complete absence of a patent artery was recognized in 6 out of 62 Vincula longa of the flexor superficialis and in 22 out of 75 of the profundus flexor. Most frequently, the Vincula longa had a single artery and a single vein. Considering the constant presence of vessels on the cross section, the Vinculum breve is regarded as essential for maintaining the tendons at work. In contrast, the significance of Vinculum longum will be variable for the microcirculation of intravaginal segments of the flexor tendons individually and also in the course of aging.