Anatomical analysis of antebrachial cutaneous nerve distribution pattern and its clinical implications for sensory reconstruction

Abstract

This study aimed to reveal the distribution pattern of antebrachial cutaneous nerves and provide a morphological basis for sensory reconstruction during flap transplantation. Forearm specimens containing skin and subcutaneous fat were obtained from 24 upper extremities of 12 adult cadavers. Cutaneous nerves were visualized using modified Sihler's staining. Then the data was used to show the distribution pattern and innervation area of the forearm cutaneous nerve. The anterior branch of lateral antebrachial cutaneous nerve innervates 26% of the medial anterior forearm; the posterior branch innervates 38.21% of the lateral anterior forearm and 24.46% of the lateral posterior forearm. The anterior branch of medial antebrachial cutaneous nerve innervates the medial aspect of the forearm covering 27.67% of the anterior region; the posterior branch the lateral part of the forearm covering 7.67% and 34.75% of the anterior and posterior regions, respectively. The posterior antebrachial cutaneous nerve covers 41.04% of the posterior forearm. Coaptations were found between the branches of these cutaneous nerves. The relatively dense secondary nerve branches were found in the middle 1/3 of the lateral anterior forearm and the middle 1/3 of the medial posterior forearm. The relatively dense tertiary nerve branches were the middle 1/3 and lower 1/3 of the medial anterior forearm. The intradermal nerve branches were the relatively dense in the middle 1/3 of the medial anterior and lateral posterior forearm. The middle 1/3 of the medial and lateral forearm had the relatively dense total nerve branches. These results can be used sensory matching while designing forearm flaps for reconstruction surgeries to obtain improved recovery of sensory.

Fig 1. Sketch map of forearm division.

(A) Anterior forearm. (B) Posterior forearm.

Fig 2. Distribution pattern of the right forearm cutaneous nerve.

(A) Sihler's staining. (B) Patterns in Figure A. ABLACN: anterior branch of lateral antebrachial cutaneous nerve, PBLACN: posterior branch of lateral antebrachial cutaneous nerve, ABMACN: anterior branch of the medial antebrachial cutaneous nerve, PBMACN: posterior branch of the medial antebrachial cutaneous nerve, PACN: Posterior cutaneous nerve of forearm. Ruler is cm.

Fig 3. Sihler's staining revealed the distribution of intradermal nerves in the middle 1/3 area of the lateral posterior region of the right forearm.

Red arrow points to twisted knotted nerve branch. Ruler is cm.

Fig 4. Distribution pattern and innervation area of the forearm cutaneous nerve.

(A) Sketch map of cutaneous nerve distribution in the anterior forearm. The light blue and light yellow frames represent the ideal donor sites for the design of flaps with ABLACN and ABMACN, respectively. (B) Sketch map of cutaneous nerve distribution in the posterior forearm. The dark blue, dark yellow and the green frames represent the ideal donor site for the design of flaps with PBLACN, PBMACN and PACN, respectively. (C) Area innervated by cutaneous nerves of anterior forearm. (D) Area innervated by cutaneous nerves of posterior forearm.