Anatomy study and clinical application of rectangular flap from dorsal index finger based on the first dorsal metacarpal artery

Objective To dissect and measure the first dorsal metacarpal artery and the dorsal branch of proper digital artery in fresh hand specimens, and explore the therapeutic effect of rectangle flap from dorsal index finger to repair avulsed thumb injury, and to discuss the operation and outcome of the flap for tissue defect of thumb. Methods From February, 2006 to February, 2014, the first dorsal metacarpal artery and the dorsal branch of proper digital artery from 6 fresh adult hand specimens perfused by red latex were explored. Twenty-one thumbs with skin defect in degloving injury patients were treated with rectangle flap from index finger based on the first dorsal metacarpal artery. And the dorsal branch of index finger proper nerver was anastomosed to reconstruct the feel of pulp of thumb finger. The size of the flaps ranged from 3.2 cm × 4.3 cm to 4.8 cm × 2.5 cm. The donor was covered by skin graft from groin. Results The first dorsal metacarpal artery originated from the radial artery between the second metacarpal and the extensor pollicis longus. The distal branch of the first dorsal metacarpal artery anastomosed with the dorsal branches of the proper artery of index finger. All flaps survived and were followed up for 6-35 months, an average of 17.4 months. The function of the thumb was well. And the thumb restored satisfactory appearance, restored the S3+ pulp feeling. Two-point discrimination restored 6-11 mm (average, 8.6 mm). There was no scar contracture, tendon adhesion and complications such as sensory disturbance in donor area. Conclusion The first dorsal metacarpal artery anastomosed with the dorsal branch of the proper artery of proximal index finger. The dorsal branches of proper artery in proximal and middle segments of index finger composed of the dorsal vessel network. Repairing soft tissue of thumb with dorsal rectangle flap of index finger based on the first dorsal metacarpal artery is recommendable. It can be easily and conveniently performed. Key words: Surgical flaps; First dorsal metacarpal artery; Proper digital artery; Index finger; Applied anatomy; Finger injuries