Vascular anatomy of the digital extensors.

Fifty upper extremities from fresh human cadavers age range 20 to 80 years were used in the study of the vascularization of the tendons of the digital extensor muscles. The blood supply to the tendon originates from different sources at different levels. At the level of the musculotendineal junction the tendon receives the blood supply through the arteries of the fleshy part of the muscle. In the synovial sheath the arteries reach the tendon through the mesotendon. In the metacarpal region and on the back of the digits the arteries reach the tendon through the paratenonium and through the branches of the digitopalmar arches. In all cases and at all levels the arterial branches to the extensors divide in a "T" shape manner into an ascending and a descending branch. Some areas of the tendon which are exposed to the less favourable mechanical conditions receive less blood supply.