INTRODUCTION
Despite this new technique and new concept of vascularized island transfer, repeated failures after repetitive secondary ruptured tendon transfers with pulley reconstruction were encountered in multioperated and scarred recipient beds. However, throughtout these clinical dissections, the excellence of both intrinsic and extrinsic vascularization of the plexor digitorum sublimis of the ring finger had been noted, due largely to three small mesovascular pedicles of ulnar origin, just before Guyon's canal. Other flexion structures, such as pulleys from A 1 to A4, and the digital sheath were vascularized by the collateral vessels and branches supplying the metacarpophanlangeal and interphalangeal joints depending on the same vascular ulnar system.
Theoretically, venous return should be provided by the two small veins accompanying the ulnar artery. However, in pratice, these veins are of small diameter and are not suitable for anastomoses.