Communications between the palmar digital branches of the median and ulnar nerves: A study in human fetuses and a review of the literature

Abstract

In this study, median nerves (MNs) and ulnar nerves (UNs) were dissected in 200 palmar sides of hands (left and right) of 100 (50 male, 50 female) spontaneously aborted fetuses with no detectable malformations. The fetuses, whose gestational ages ranged from 13 to 40 weeks, were dissected under an operating microscope. The MN divided first into a lateral ramus and a medial ramus and then formed a common digital nerve. The first common digital nerve trifurcated in all of the studied cases. The branching patterns were classified into two types (Type 1 and Type 2) based on the relationship with the flexor retinaculum (behind/distal of it). A communication branch between the UNs and MNs in the palmar surface of the hand was found in 59 hands (29.5%). The proper palmar digital nerves were numbered from p1 to p10, starting from the radial half of the thumb to the ulnar half of the little finger, and these nerves exhibited six types of variations. The present data obtained from human fetuses will aid in elucidating the developmental anatomy of the nervous system and provide hand surgeons with a more complete anatomical picture to help them to avoid iatrogenic injuries.

Median and ulnar nerve anastomoses in the upper limb: A meta‐analysis

“…For RCA, 4 studies reporting data were cadaver, and 2 were electrophysiological . A total of 10 studies concerning BA were cadaver, and only 1 was electrophysiological…”

“…A total of 11 studies ( n = 1,768 hands) reported the prevalence of BA . The overall pooled prevalence of BA was 60.9% (95% CI, 36.9%–82.6%; Cochran Q, P < 0.001; I‐squared = 98.5%, 95% CI, 98.1%–98.9%) (Table ; Fig.…”

“…Data on types of BA were reported in 10 studies ( n = 486 hands) . The analysis found that the most frequent type of BA was type 1, with a pooled prevalence of 86.2% (95% CI, 77.3%–91.6%).…”

“…The characteristics of included studies are summarized in Supplementary Tables S1–S4 (available online), which include the prevalence of anastomoses in upper limbs as reported by the individual studies. A total of 41 studies ( n = 6,409 upper limbs) reported data on MGA, 12 studies ( n = 1,884 upper limbs) reported data on MA, 6 studies ( n = 501 upper limbs) reported data on RCA, and 11 studies ( n = 1,768 upper limbs) reported data on BA and were included in the meta‐analysis.…”

Anatomical study of sensory anastomoses in the hand

“…In the late 19 th century began the first detailed descriptions of the anastomosis by Berretini. Meals and Shaner, 6 Dogoan et al 8 . were the first to classify this communication according to their anatomical directing, and Ferrari and Gilbert 9 (Figure 1) described its anatomical and angular measurement compared with the transverse carpal ligament.…”