Reconstruction of the plantar toe with a distal reverse instep sensory island flap

Abstract

Plantar toe ulcers are a challenging surgical problem. There are several methods for reconstruction, but no attention has been given to the preservation of sensation. This report proposes a method to provide protective sensation for the reconstructed area. The ulcers of seven patients ranged from 2 × 3 to 7 × 3 cm with defects of the plantar first toe and distal metatarsus, including four burns, a trauma, a diabetic ulcer, and a neuropathy injury reconstructed with a distal reverse instep sensory island (DRISI) flap. The patients were 21-38 years old. The second metatarsus medial nerve was co-opted using the end-to-side method to the adjacent lateral nerve, then its proximal stump provided the donor nerve for the sensation of the flap. Patients were assessed in terms of protective sensory functions, including touch, pain, dermatomeric somatosensory-evoked potentials (SEP), thermal sensation and Semmes-Weinstein monofilament (SWM) light touch. The flaps ranged from 2 × 3 to 7 × 3 cm. All transferred flaps to the plantar first toe survived. No complications were observed at the donor and flap sites. Patients were followed-up 8-24 months. Except for two cases, all nerves of the donor and flap sites exhibited protective sensation, including positive SEP responses between 44 and 50 ms and positive SWM responses ≤ 3.84. The DRISI flap can be used for the reconstruction of various plantar first toe defects with acceptable protective sensation. End-to-side neurorrhaphy provides a sensory nerve end to subsequent end to end co-optation to the flap nerve for protective sensation.