Single-Incision Carpal Tunnel Release and Distal Radius Open Reduction and Internal Fixation: A Cadaveric Study

Abstract

Background: The safety of surgical approaches for single- versus double-incision carpal tunnel release in association with distal radius open reduction and internal fixation remains controversial.

Purpose: The purpose of this study was to identify critical structures to determine if a single-incision extension of the standard flexor carpi radialis (FCR) approach can be performed safely.

Methods: Nine cadaveric arms with were dissected under loupe magnification, utilizing a standard FCR approach. After the distal radius exposure was complete, the distal portion of the FCR incision was extended to allow release of the carpal tunnel. Dissection of critical structures was performed, including the recurrent thenar motor branch of the median nerve, the palmar cutaneous branch of the median nerve (PCBm), the palmar carpal and superficial palmar branches of the radial artery, and proximally the median nerve proper. The anatomic relationship of these structures relative to the surgical approach was recorded.

Results: Extension of the standard FCR approach as described in this study did not damage any critical structure in the specimens dissected. The PCBm was noted to arise from the radial side of the median nerve an average of 6.01cm proximal to the proximal edge of the transverse carpal ligament. The PCBm became enveloped in the layers of the antebrachial fascia and the transverse carpal ligament at the incision site, protecting it from injury. The recurrent motor branch of the median nerve, branches of the radial artery and the median nerve proper were not at risk during extension of the FCR approach to release the carpal tunnel.

Conclusions: Extension of the standard FCR approach to include carpal tunnel release can be performed with minimal risk to the underlying structures. This exposure may offer benefits in both visualization and extent of carpal tunnel release.

Keywords: acute carpal tunnel release; distal radius volar plating; extended flexor carpi radialis approach; motor recurrent; palmar cutaneous branch median nerve.

Fig. 1

An 8 to 9 cm incision is made overlying the FCR tendon and zigzagged across the wrist crease. FCR, flexor carpi radialis.

Fig. 2

The space of Parona is dissected. The radial artery (black arrow) and pronator quadratus (white arrow) are identified.

Fig. 3

Extension of the FCR approach from its distal aspect (point A) to a standard carpal tunnel approach marked in line with the ulnar border of the ring finger (points B and C). FCR, flexor carpi radialis.

Fig. 4

A gently curved incision connects the FCR incision to the standard carpal tunnel approach. FCR, flexor carpi radialis.

Fig. 5

The recurrent thenar motor branch of median nerve (arrow A) and PCBm (arrow B) becoming enveloped by layers of antebrachial fascia and transverse carpal ligament. PCBm, palmar cutaneous branch of the median nerve.

Fig. 6

(Top) Distal course demonstrating dual PCBm, depicted by arrows. (Bottom) PCBm splits giving rise to two major branches. PCBm, palmar cutaneous branch of the median nerve.