Investigation of the dorsal cutaneous nerve injury risk and portal safety related to wrist surgery: an anatomical study

The aim of this study was to define the branching patterns and innervation regions of the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve and to evaluate the distance from 1–2, 3–4, 4–5, midcarpal radial, midcarpal ulnar, dorsal radioulnar joint, 6-radial, 6-ulnar dorsal arthroscopy portals to certain landmarks on the dorsal surface of the hand and wrist. Forty hands and wrists of 20 formalin-fixed intact cadavers without any known pathology, surgical scars or trauma were examined in the Macroscopy Laboratory of Ege University Faculty of Medicine, Department of Anatomy. Arthroscopy portals were placed using a dorsal approach to the wrist in the dissection method. In our study, the distances between the closest branch to the portal of the superficial branch of the radial nerve and the 1–2, 3–4, and midcarpal radial portals were 3.7 ± 2.0, 9.7 ± 3.8, and 8.0 ± 3.4 mm, respectively. And the distances between the closest branch to the portal of the dorsal branch of the ulnar nerve and the 4–5, 6-radial, 6-ulnar, and midcarpal ulnar portals were 18.3 ± 3.8, 7.1 ± 4.4, 2.5 ± 1.8, and 15.4 ± 4.4 mm, respectively. This study demonstrated that the results can guide surgeons in procedures such as the pin fixation of distal radius fractures, where surgeons may not always perform blunt dissection or expose nerves. The findings of the portal replacement would help any surgical procedure on the dorsal wrist be performed with caution.