The vascularization of the human flexor pollicis longus tendon.

The vascularization of the human flexor pollicis longus tendon was outlined by the use of microangiographic techniques, applied on freshly amputated arms. At the insertion of the tendon there was regularly a very well developed vinculum brevis, often extending proximally to the middle of the base phalanx of the thumb. Proximally to the metacarpo phalangeal joint there was a mesotenon of various shape, originating from the volar-ulnar (non-friction) side of the synovial tendon sheath. There seemed to exist a non-interrupted intrinsic longitudinal vascular system in the tendon, and the vessels were located in those parts of the tendon which are not subjected to friction.