Superficial Radial Nerve Transection Improves Sensory Outcomes in First Dorsal Metacarpal Artery Flaps

BACKGROUND: This article reports the operative technique and clinical effect of repairing thumb pulp defects using a modified first dorsal metacarpal artery flap method. In this method, the dorsal branches of the radial and ulnar proper digital nerves of the index finger were preserved but the superficial branches of the radial nerve were transected. METHODS: Data obtained from 121 patients with thumb pulp defects who were admitted to the authors' hospital from June of 2011 to December of 2014 were retrospectively analyzed. Patients were divided into two groups based on whether the superficial branches of the radial nerve were transected. The dorsal branches of the radial and ulnar proper digital nerves of the index finger and the proper digital nerves in the wound were coapted using the end-to-end style. Static two-point discrimination, Semmes-Weinstein monofilament scores, pain, cold intolerance of the reconstructed finger, allachesthesia, and patient satisfaction were compared between the two groups. RESULTS: The authors observed significant differences in static two-point discrimination, Semmes-Weinstein monofilament flap score, pain of finger pulp, allachesthesia duration, and patient satisfaction (p < 0.05). The transection group presented slightly better discriminatory sensation in the flap and higher patient satisfaction. In addition, the duration of allachesthesia in the transection group was significantly shorter than that in the preservation group. CONCLUSION: In the repair of thumb pulp defects using a modified first dorsal metacarpal artery flap carrying the dorsal branches of the radial and ulnar proper digital nerves of the index finger, transecting the superficial branches of the radial nerve achieved better clinical outcome compared with preserving them. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.