Compression Syndromes of the Ulnar Nerve

Cubital tunnel syndrome is the second most common compression syndrome of a peripheral nerve. It is significantly less common than the 10 times more frequent carpal tunnel syndrome and its pathogenesis is still controversial, as evidenced by the inconsistent nomenclature. It was previously referred to as sulcus nervi ulnaris syndrome and is known in neurological nomenclature under the term UNE (ulnar neuropathy at the elbow). The complex and risky ventral relocation of the ulnar nerve with its various variants (subcutaneous, submuscular) has largely been replaced by simple decompression. Alternatively, minimal medial epicondylectomy has its proponents. Endoscopic procedures are increasingly being used. However, based on the current state of research, this does not result in clear advantages or disadvantages (analogous to carpal tunnel syndrome). A rare compression site is found at the wrist—as Loge-de-Guyon syndrome—or an even more distally located compression of the deep branch of the ulnar nerve. The most common causes are external pressure paresis (“cyclist’s paralysis”) with a good spontaneous prognosis, but also ganglion cysts or other space-occupying lesions that require surgical treatment.