Anatomy research and clinical application of reverse dorsoradial thumb flap of different rotation point in repairing defect of thumb

Objective To investigate a anatomy research and clinic application of defect of thumb by reverse dorsoradial thumb flap of different rotation point. Methods The origin, course, distribution and vascular chain of the first metacarpal dorsoradial artery of thumb from 11 adult cadaveric hand specimens perfused by red latex were explored from September, 2012 to December, 2016. There were 3 different rotation points: the proximal of the metacarpophalangeal joint, proximal basal of the first proximal phalanx and distal of the first proximal phalanx. Each could be used as reverse flow flap to repair the defect of thumb. Results The first metacarpal dorsoradial artery of thumb originated from the radial artery and the initial diameter was (0.68±0.26) mm, diagonally across the extensor pollicis brevis tendon and then along the radialis part and terminated in the proximal of the first proximal phalanx of the vascular chain. There was a constant communicating branch among the proximal metacarpophalangeal joint, proximal basal of the first proximal phalanx and digital arterial dorsal branch. All the proximal of the metacarpophalangeal joint 4.3 mm to 10.2 mm and proximal basal of the first proximal phalanx 4.9 mm to 7.2 mm could be used as the rotation point of the flap. The flap of the first promixal phalanx blood supply was based on the vascular chain of neurocutaneous. There was a constant dorsal branch of the pollical artery, which was 8.6 mm to 10.3 mm far from the interphalangeal joint, could be used as the rotation point of the flap. Twenty-four cases with soft tissue defects of thumb were repaired by reverse dorsoradial flap. The flap size ranged from 2.0 cm×1.5 cm to 3.5 cm×2.8 cm. The follow-up period was 3 months to 12 months, protective sensations were restored, and skin flap two-point discrimination were 9.0 mm to 12.0 mm. The appearance of the thumbs was satisfactory. Conclusion Different rotation point of reverse dorsoradial flap can successfully repair the defect of thumb. The operation has advantages of simple, reliable blood supply, high success rate and is an ideal option for reconstruction the defect of thumb. Key words: Thumb; Surgical flaps; First metacarpal dorsoradial artery of thumb; Finger injuries; Microsurgical operation; Applied anatomy