The Palmar Cutaneous Branch of the Median Nerve: A Detailed Morphometric Study

Abstract

Damage to the palmar cutaneous branch of the median nerve (PCBMN) is a potential complication of surgery at the volar aspect of the wrist. The aim of this study was to determine the relationships of the PCBMN to both surface and bony landmarks using reliable methods. Ten pairs of forearms from cadavers aged 73 to 98 years were dissected. The PCBMN was identified and its course and relationships documented. The situation of the PCBMN was quantified relative to the distal wrist crease, bistyloid line, scaphoid tubercle, radial styloid process and flexor carpi radialis tendon. A PCBMN was identified on 90% of sides. The PCBMN arose from the radial aspect of the median nerve 52.4 (SD 31.0) mm from the bistyloid line and entered the transverse carpal ligament 10.9 (SD 9.5) mm proximal to the bistyloid line. At the level of the distal wrist crease the PCBMN was located 0.6 to 7.5 mm (mean 4.5; SD 1.9 mm) from the ulnar aspect of the flexor carpi radialis tendon. The inter-and intra-observer reliability of the measurement methods ranged from ICC 0.96 to 1.00. Detailed morphometric data of the PCBMN relative to bony landmarks contribute to knowledge of the spatial relationships of the PCBMN to inform the precision of surgical incisions.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice

“…The prevalence of the PBMN is over 90% ( 72 , 77 ) . In its absence, other nerve branches has to replace its sensory innervation area, e.g., the palmar branch of ulnar nerve.…”

“…10 B–F , are of clinical importance, as harm may result in dysesthesia and pain on wrist extension ( 55 , 73 , 78 ) . The course of the PBMN often varies when comparing both sides ( 77 ) .…”