Anatomical study of first palmar intermetacarpal flap in cadavers and application for congenital first web contracture in a child with Apert's syndrome.

Introduction: Reconstructing severe first web contractures often involves using either pedicled forearm flaps, which can cause extensive scarring, or free flaps, which can be highly complex. In this study, we present a local palmar hand flap that overcomes both of these challenges.

Methods: Ten fresh upper limbs were examined after arterial injection with colored latex. The study focused on identifying the most distal palmar vascular cutaneous branches suitable for designing an elliptical cutaneous flap over the volar intermetacarpal area. This flap's width was approximately 50% of the width of the thenar eminence. Additionally, we present the case of an 8-year-old child with a type 1 Upton's Apert's hand, which exhibited a severe first web contracture.

Results: In seven cadaver hands, one distal cutaneous perforator was found, while in three hands, two perforators were identified. These perforators originated from the thumb radial collateral artery six times, pollex princeps three times, index radial collateral vessels twice, and thumb ulnar collateral vessels twice. The mean perforator diameter was 0.5 mm (ranging from 0.4 to 0.6 mm), and the mean perforator length was 10 mm (ranging from 0.8 to 12 mm). Using this flap bilaterally in our patient resulted in a straightforward procedure that created a broad and functional first web. A total-thickness skin graft was necessary to cover the proximal thenar area, and fortunately, no complications arose. A wide first web with an intermetacarpal angle of 40° ultimately was obtained scoring 8 on the kapandji.

Conclusions: The first palmar intermetacarpal flap presents itself as a reasonable and uncomplicated option for addressing significant moderate-to-severe first web contractures.