Reconstruction of Proper Digital Nerve Defects in the Thumb Using a Pedicled Nerve Graft

A proper digital nerve (PDN) defect in the thumb can produce partial or complete sensory loss which can result in functional disability. This article reports the treatment of the thumb PDN defect using a pedicled nerve graft harvested from the dorsal branch of the PDN. Fourteen patients with the thumb PDN defect underwent a new surgical procedure in which the pedicled nerve graft was used to bridge nerve defect. For comparison, the investigators also collected a consecutive series of 21 patients with thumb PDN defects treated using a nonvascularized sural nerve graft. This study was designed to evaluate the efficacy of pedicled nerve grafting for PDN defects in the thumb.

At final follow-up, the investigators measured the sensibility of the thumb pulps and the donor sites using the Semmes-Weinstein monofilament test and static 2-point discrimination (2PD) test. The test points were at the centers of the radial and ulnar portions of the thumb pulp and the donor sites separately. Each area was tested 3 times with a Dellon-Mackinnon discriminator. Two out of 3 correct answers were considered proof of perception before proceeding to another lower value.

Inclusion Criteria:

1. thumb PDN defects between the middle of the distal phalanx and the metacarpophalangeal joint;
2. PDN defects of single or both sides;
3. PDN defects 1-4 cm in length.

Exclusion Criteria:

1. injury to the course of the pedicle or the donor sites;
2. PDN defects less than 1 cm or longer than 4 cm;
3. no Doppler sound at the location of the second dorsal metacarpal artery (SDMA).