Conception d’un modèle anatomique pour l’étude des différents tracés d’incision des pollicisations de l’index pour le traitement des aplasies congénitales du pouce

Abstract

Thumb hypoplasia or aplasia represents 4.6% of congenital hand anomalies. In Blauth stages IIIB, IV and V, index finger pollicization can be proposed. Different incisions have been described in literature. Skin incisions are important because they determine the exposure of the underlying structures, the cosmetic result of the new thumb and the functional result of the first web space. The aim of this study was to create an anatomical framework to study different incisions in index finger pollicization for congenital thumb aplasia. The anatomical study was carried out from the two upper limbs of the same cadaver. An anatomical model of thumb aplasia was created on one hand (surgical resection of the thumb, the thenar muscles and the trapeze). A similar resection was carried out on the other hand, followed by index finger pollicization. These two models were then molded with resin plaster. Coming from the same cadaver, they had the similar dimensions (height, length, circumference of fingers and palm). An appropriately sized surgical glove was prepared by cutting of the thumb. The resulting hole was closed with cyanoacrylate glue. The “thumbless” anatomical model was then fitted with this 4-fingered glove to study incisions described by 4 different authors: Foucher, Ezaki, Buck-Gramcko and Blauth. On this template, the gloves were marked and cut along the described landmarks and resulting flaps were then positioned on the pollicized hand. This setup allowed a comparative analysis of scars position, first web space size, new thumb aspect (two or three phalanges) and the amount of cutaneous resection. This work presents a standardized, reliable model to study and compare different skin incisions in index finger pollicization. The model can be used for educational purposes, either to teach or optimize a given incision set.