Blood supply of the flexor pollicis longus tendon.

The blood supply of the flexor pollicis longus tendon was investigated by arterial injections of india ink--latex-barium-solution in 15 fresh, adult cadaver upper extremities. In the digital area vascularity was by way of two vincula (V1 and V2). V1, located just proximal to the metacarpophalangeal joint and the A1 pulley, originated either from both digital arteries or from the princeps pollicis artery alone. V2, located at the interphalangeal joint level under the A2 pulley, originated from both digital arteries. In the predigital area branches of the median nerve artery supplied the area from the base of the thumb to the musculotendinous junction; in addition, the microvascular network of the mesotendon contributed to this area. Intratendinous vascularization was more abundant in the predigital area.