Ulnar nerve anatomy and its application around the wrist

The ulnar nerve primarily supplies the intrinsic muscles and sensation to the ulnar aspect of the hand. In high ulnar nerve palsies, whether traumatic or due to compressive neuropathy, motor and sensory recovery is often suboptimal due to the long distance between the lesion and the target organ. Consequently, anterior interosseous nerve transfer near the wrist is now frequently employed to enhance ulnar nerve recovery. Additionally, ulnar tunnel syndrome (UTS) is a well-described, albeit relatively uncommon, ulnar compressive neuropathy occurring around the hand and wrist at Guyon's canal. Compression involving the ulnar nerve, its deep branch, or its superficial branch may lead to various clinical presentations of UTS, typically sparing the dorso-ulnar sensation of the hand. Beyond neuropathies, this topic will also address the sympathetic fibers originating from the ulnar nerve, known as the nerve of Henle, in relation to the treatment of Raynaud's phenomenon. This vasospastic disorder can cause not only Raynaud's triad but also non-healing ulcers and even distal gangrene.