Review Question - QID 212932

The dorsal sensory branch of the ulnar nerve is not at risk during the establishment of the 4-5 portal.

Complications of wrist arthroscopy occur in 1-2% of patients. The superficial sensory branch of the radial nerve is located 16mm from the 3-4 portal and may be injured during placement of the 1-2, 1U, and 1R portals. The dorsal sensory branch of the ulnar nerve is located 8mm from the 6R portal and may be injured during placement of the 6U and 6R portals.

Shyamalan et al. performed a cadaveric study and systematic review of the structures at risk during wrist arthroscopy. They found that the dorsal sensory branch of the ulnar nerve was found to be at risk by performing the 6U, 6R and ulnar midcarpal (MCU) portals; the sensory branch of the radial nerve by the 1-2 and 3-4 portals; and the posterior interosseous nerve by the 3-4 and 4-5 portals.

Longo et al. performed a study to determine the safety of dorsal wrist arthroscopy portals using MRI. They found that the 1-2 and 6U portals likely increase the risk of neurovascular damage because of their proximity to neurovascular structures. The 3-4 and 4-5 portals, on the other hand, are the farthest away from the neurovascular structures and likely reduce the risk of damage to neurovascular structures.

Illustration A is a diagram depicting portal locations and their relationship to the superficial sensory branch of the radial nerve and dorsal sensory branch of the ulnar nerve.

Incorrect Answers:
Answers 1, 2, 4, and 5: Each of these combinations are correct. The superficial sensory branch of the radial nerve may be injured during placement of the 1-2, 1U, and 1R portals, while the dorsal sensory branch of the ulnar nerve may be injured during placement of the 6U and 6R portals.