Arch Hand Microsurg.  2022 Mar;27(1):49-53. 10.12790/ahm.21.0146.

Variation of the palmar cutaneous branch of the median nerve identified within the tendon sheath of the flexor carpal radialis

• Park HS
• Choi SW
• Bae JY

• KMID: 2526648
• DOI: http://doi.org/10.12790/ahm.21.0146

Abstract

Purpose
During volar plate fixation of distal radius fractures, we have encountered patients with an anomalous course of the palmar cutaneous branch (PCB) of the median nerve within the sheath of the flexor carpi radialis (FCR) tendon. The purpose of this study was to assess the frequency and location of variations of the PCB within the sheath of the FCR tendon.
Methods
This retrospective study enrolled 83 patients who underwent volar locking plate fixations through a modified Henry approach for distal radius fractures from July 2018 to April 2020. When we encountered an anomalous PCB within the sheath of the FCR tendon, we documented the specific finding and location where the PCB entered the sheath of the FCR tendon.
Results
There were nine patients (10.8%) who had an anomalous course of PCB penetrating the sheath of the FCR tendon. The average entering point of PCB into the sheath of the FCR tendon was 3.07 cm from the distal wrist crease (range, 2.5–3.6 cm).
Conclusion
An anomalous course of the PCB entering the sheath of the FCR tendon was observed at a high frequency (10.8%). Care must be taken not to injure the PCB during a dissecting of the FCR sheath during a modified Henry approach for a distal radius fracture.

Keyword

Palmar cutaneous branch; Median nerve; Distal radius fracture; Flexor carpi radialis; Modified Henry approach

Figure

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  Fig. 1. Intraoperative photo of patient 1. An anomalous course of the palmar cutaneous branch of the median nerve (*) is found within the floor of the flexor carpi radialis sheath. The flexor carpi radialis tendon is retracted to the ulnar side.

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  Fig. 2. Intraoperative photo of patient 3. The palmar cutaneous branch (*) is found within the floor of the flexor carpi radialis sheath. A layer of fat is observed around the nerve.

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  Fig. 3. Schematic of the variations of the palmar cutaneous branch (PCB) of the median nerve. a, PCB crossing the dorsal side of the flexor carpi radialis (FCR) sheath. b, PCB crossing the volar side of the FCR sheath. c, PCB penetrating the sheath of the FCR (*entering point). d, PCB with normal course. PL, palmaris longus.

Reference

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